Steps for Changing a Light Switch

Bob Formisano is a certified architect and builder who boasts nearly four decades of expertise in constructing new residences and renovating historic properties. He has a particular focus on restoring outdated systems from the 1920s, such as galvanized plumbing and knob-and-tube electrical wiring. For over a decade, he has contributed articles on home repairs.

Project Summary

• Duration of Work: 45 minutes
• Overall Duration: 45 minutes

• Proficiency Level: Intermediate
• Projected Expense: $2 to $8

Acquiring the ability to change light switches in your home is a valuable skill that can be relatively straightforward, particularly when dealing with single-pole switches that manage a light fixture or outlet from a single location on the wall. Given their frequent use, wall switches can wear out over time and require replacement. Signs that a wall switch needs to be replaced include a loss of its snap, a loose feel, buzzing or crackling sounds during operation, or a failure to control the light fixture. Additionally, you might want to refresh the appearance of your switches, transitioning from a toggle to a rocker style. Continue reading to discover the easy steps for replacing a single-pole light switch.

Wiring for Light Switches

Changing a light switch is typically a simple process that involves detaching two hot wires from the existing switch and connecting them to a new one. In the case of a standard single-pole switch, it’s not necessary to worry about which hot wire connects to which terminal, as they can be swapped. The most important aspect is to note how the wires are connected to the old switch and ensure they are connected in the same manner to the new switch.

Every new switch you acquire will feature a green grounding screw attached to the mounting strap. When you replace an existing switch, it’s essential to connect the new switch to the circuit’s ground wires, regardless of whether the old switch had a grounding connection.

Prior to Getting Started

Deactivate the electricity by turning off the circuit breaker that manages the circuit supplying the switch. In older setups that utilize fuse panels instead of circuit breakers, the power is cut off by removing the fuse that safeguards the circuit you are addressing.

Go back to the wall switch and toggle it to verify that the power is off. If it is still on, head back to the panel to find and switch off the appropriate circuit breaker.

Safety Factors to Keep in Mind

Ensure that the appropriate circuit breaker for the switch you are about to replace is turned off. Utilizing a voltage tester can help verify this. Furthermore, check that the wiring for the switch is in proper condition before proceeding with any modifications, and verify that the new switch is compatible. If you are uncertain, consider consulting a professional.

Requirements for Your Task

Gear / Instruments

• Screwdriver
• Non-invasive circuit tester
• Wire snips (optional)
• Wire stripping tool (optional)
• Long-nose pliers

Materials

• One-way wall switch
• Insulating tape (optional)
• Optional grounding pigtail (if required)
• UL-certified wire connector (optional)

Instructions

Steps for Changing a Single-Pole Light Switch

Take off the cover plate and check for electrical power.

• Take off the cover plate of the wall switch by unscrewing the mounting screws.
• Check for electrical power with a non-contact circuit tester. Place the tester’s probe into the electrical box near the screw terminals of the switch. If there is live current present, the tester will illuminate or emit a sound.

Remove the Switch.

• Once you have confirmed that the power is turned off, take out the screws that secure the strap of the switch to the electrical box.
• Gently remove the switch by pulling the straps outward.
• Exercise caution to prevent putting strain on the wires. Aging wires can become fragile, and the insulation may break if handled improperly.

Inspect the Cables

• In modern installations utilizing NM cable, the wires typically feature black insulation and are probably connected to brass or copper-colored screw terminals located either on one side or on opposite sides of the switch housing.
• In certain setups, referred to as a switch loop, a switch can be linked to a black wire and a white wire that has been labeled with black tape to signify that it functions as a hot wire.
• A green grounding screw might be connected to exposed copper grounding wires, although this is not universally applicable.
• In older switches, the wiring might be insulated with rubber or cloth, and there may be no color coding present.
• Currently, it is common to use black tape to mark these wires, indicating that they are live. If they lack color coding, it is advisable to label them at this time.

Tip

If you observe that your wall switch is connected with three or four insulated wires instead of the typical two, you are dealing with a 3-way or 4-way switch, not a standard single-pole switch.

These switches allow you to operate a light fixture from multiple wall points. While you can replace this switch, it’s essential to ensure you choose the correct type and to connect the wires precisely as they were attached to the previous switch.

Unplug and Take Out the Switch

• Pull the switch out of the box sufficiently so that you can access the screw terminals using a screwdriver.
• Unplug the circuit wires.
• Inspect the wire loop at the tip of each wire. If you notice any nicks or damage, cut away the affected section of the wire, and then remove approximately 3/4 inch of insulation to reveal fresh copper.
• If the switch is connected to the circuit ground wires via a grounding screw, be sure to detach this connection as well.

Connect a grounding pigtail if necessary.

• If your previous switch lacked a grounding connection, you should attach a grounding pigtail to the circuit’s grounding wires. The opposite end of the pigtail should be connected to the grounding terminal of the switch.
• Grounding pigtails can be found as short wires with green insulation specifically made for this function, or you can make your own by using a short piece of bare copper wire or wire with green insulation.
• Attach one end of the grounding pigtail to the grounding wires within the box. Typically, this requires you to take off the wire nut that connects the grounding wires of the circuit, then twist the end of the new pigtail together with those wires, and finally, resecure the wire nut.

Link the New Switch

• Create a C-shaped loop at the end of each wire, ensuring it curves in a clockwise direction.
• Connect the loose end of the grounding pigtail to the green grounding screw located on the switch strap.
• Wrap the wire around the screw’s shaft and then secure it tightly.
• Connect the two live wires to the screw terminals located on the side of the switch housing.
• Fully tighten the screws and pull on them to ensure they are firmly in place.

Tip

In vintage houses featuring metal electrical boxes, it can be beneficial to use electrical tape to encase the newly installed switch, ensuring the connection points and wires are protected. This precaution can help prevent circuit shorts, which may occur with aging wires and metal enclosures.

Set up the switch and attach the cover plate.

• Carefully place the wires inside the wall box.
• Fasten the switch using the mounting screws that are inserted into the holes on the box.
• Ensure that the switch is oriented correctly so that the ON/OFF label is easily readable.
• Position the switch vertically within the enclosure, then secure the cover plate in place.
• Activate the circuit by switching on the power at the breaker panel.
• Check the functionality of the switch.

Adjustable Light Switches

A dimmer switch has the ability to alter the atmosphere of a space by offering various levels of lighting. Most dimmer switches can be fitted into a standard wall box, serving as a replacement for a conventional switch. As always, ensure that the power to the switch is completely turned off prior to the installation of a dimmer switch.

When to Seek Professional Help

Changing a wall switch is considered one of the simpler electrical repairs in a home, yet there is always a risk of electric shock when dealing with electricity. If you feel uneasy about diagnosing issues or performing basic electrical tasks, it’s wise to hire a professional electrician for the job. Additionally, if you start the repair and encounter unexpected challenges, don’t hesitate to reach out to an expert for assistance.

Is it possible for me to change a light switch on my own?

Changing a light switch is a task ideally suited for a DIY enthusiast who has a background in electrical work and a basic knowledge of circuitry.

Is it possible to replace a light switch without shutting off the electricity?

While seasoned DIY enthusiasts with extensive electrical knowledge might attempt to replace a light switch with the power still on, it is generally not recommended. It is highly advisable to switch off the power before making any changes to a light switch.

What is the amount of work required to change a light switch?

Hiring an electrician to change a light switch typically ranges from $100 to $200, with an average cost around $150. The final price may vary based on your location and the specifics of the task.