Single-pole light switches are used to control power to light fixtures or receptacles from one location and are the most common type of switch found in the home. The most common style of switch is the toggle switch, but these can look pretty tired and dated over time. Upgrading to a new toggle-style switch takes just a few minutes and requires no extra wiring or special connections. If the new switch's cover plate is smaller than the original, you can make it easy on yourself and cover the old plate's outline with a slightly oversize new plate—no wall repair or touch-up paint required.
Equipment / Tools
- Utility knife
- Non-contact voltage tester
- Wire strippers
- Needle-nose pliers
- Black electrical tape (as needed)
- Single-pole rocker switch with cover plate
Turn Off the Power and Prep the Cover Plate
Turn off power to the circuit feeding the switch by switching off the appropriate breaker in your home's service panel (breaker box). If the old cover plate is painted on, carefully score around the perimeter of the cover plate with a utility knife to cut through the paint.
Remove the Old Cover Plate
Remove the cover plate screws, then pry up the plate with a thin flat-blade screwdriver. Be careful not to touch any wires inside the electrical box.
Confirm the power is off by touching each wire in the electrical box with a non-contact voltage tester. If the tester indicates voltage, return to the service panel and turn off the correct circuit breaker, then retest the wires.
Remove the Switch Screws
Remove the mounting screws at the top and bottom of the switch mounting strap that secure the switch to the electrical box. Gently pull the switch body out and away from the electrical box so you can access the wire connections, which may be on the back of the switch body.
Check the Wiring
Check the wiring for condition and proper markings. Single-pole switches always connect to two hot wires. One wire will almost certainly be black. The other hot wire may be red or white. If it is white, it should have a band of black or red electrical tape near its end, indicating that it is serving as a hot wire. In other cases, the white wire may be connected to the switch with no tagging indicating it is hot. If that's the case, the prior electrician did not properly mark the wire, and you should mark it as a hot wire by wrapping it with a band of black electrical tape after disconnecting it.
The switch also should have a bare copper or green insulated ground wire connected to its ground screw (old wiring systems may not have a ground wire). The electrical box may contain white neutral wires that are connected together.
Standard single-pole switches do not connect to neutral wires. However, some "smart switches," which can be controlled by a phone or other device, include a neutral connection to provide a small amount of current so the switch can receive a wireless signal.
Remove the Old Switch
Disconnect the old switch by disconnecting the two hot wires that connect to the switch. Usually, this will involve loosening the screw terminals and removing the switch. Or, the wires may be connected with push-in fittings. For push-in fittings, there is usually a slot or opening into which you can push a small screwdriver blade or nail to loosen the connection and pull out the wire. Alternatively, you can remove the old switch by cutting the old wires off close to the switch, using wire strippers. Just make sure to leave enough length to attach the new switch. Typically, you should have at least 6 inches of extra wire.
Strip the Wire Ends (as needed)
Strip about 3/4 inch of insulation away from the two hot wires and ground wire, using wire strippers, if necessary. If the existing ends of the wires are nicked or otherwise damaged, clip them off and strip off 3/4 of insulation, leaving clean wires. Bend the exposed copper end of each wire (as needed) into C-shaped loops, using needle-nose pliers.
If the hot circuit wires are so short that they're hard to work with, you can extend the connections by adding pigtail wires (joined to the circuit wire with wire connectors), then connect the pigtails to the switch.
Orient the New Switch
Note that the switch will either be marked "TOP" or it will have a brass plate or some other distinguishing mark noting the top end. This proper orientation is important. Although the switch will still work upside down, it makes for a confusing and unprofessional installation.
Connect the New Switch
Hook the ground wire around the ground screw terminal on the switch so the hook wraps around the screw in a clockwise direction. This will cause the loop to tighten up when the screw is tightened. Tighten the screw with a screwdriver.
Connect each of the two hot wires to one of the two main screw terminals on the switch, and tighten the terminal, as with the ground screw. The two terminals are interchangeable and either wire can go to either terminal, but only one wire can be under each terminal. Tug on the wires to make sure they are secure.
Although your switch may have push-in fittings, most electricians avoid these, as screw terminal connections are more secure and less likely to loosen over time.
Mount the Switch to the Box
Gently push the new switch into the box, folding the wires neatly into the box behind the switch. Fasten the switch to the box with the two long mounting screws at the top and bottom of the switch mounting strap.
Check the Cover Plate Size
Test-fit the cover plate by placing it over the switch. if the new plate does not completely cover the outline of the old plate, buy a larger cover plate that fits the switch model.
Install the Cover Plate and Test the Switch
Install the cover plate, using the provided screws (some rocker switches have a base cover that screws into place and a top cover that snaps onto the base). Be careful not to overtighten the screws, which can bend or crack the cover plate. Turn on the power by switching on the circuit breaker, then test the switch for proper operation.