How to Change a Light Switch


If your light switch suddenly stops working, it needs to be replaced. However, calling for a repair service could be pretty expensive so it’s more practical to just change a light switch on your own. Some homeowners also choose to change a light switch or upgrade it for aesthetic purposes. It may look complicated but, changing a light switch is actually a simple and inexpensive DIY project.

To successfully replace your light switch, it’s important to understand how the switch is wired. When you turn on a light switch, the power goes through a specific wire and then back to a neutral wire to the ground. There are also wires that serve as a backup to divert the power safely away in case there is an electrical fault.

Most modern switches are designed with a screw terminal on each side. There could also be holes in the back to let the end of the wires through. Plug-in connections are usually more convenient but they are less reliable than those with screw terminals.

Removing the Light Switch

To be able to change a light switch, you must first remove it from the wall. The first thing you need to do is to loosen the screws. You can easily do this by using a standard screwdriver. Loosen the screws on each side of the device by turning the screwdriver counterclockwise. It may be tricky to get the wires out of the back and to remove them, simply insert the blade of a small screwdriver into the slot under the hole. This is where the wires are inserted. Push the screwdriver in as you pull the wires loose. Doing this will help release the grip on the inserted wire.

Where Do the Wires Go?

As mentioned, it’s important to understand how your light switch is wired to properly change a light switch. It will also help you avoid any accidents or injury. Here are some descriptions of the wires and their locations.

  • White

    The white wire is also called the neutral wire. It connects to the silver screw or you can place it in the back wire hole. It will be on the same side of the device as the silver screw.

  • Black

    The black wire is also called the hot wire. This wire goes to the brass screw. It could also go into the hole at the back of the device which is the same side as the brass screw. In some instances, this wire is red.

  • Green

    The green wire is sometimes bare copper or ground. If the device has a green or ground wire, it will be attached to the green screw terminal on the switch. It could also be in the electrical box.

Usually, there are two black wires that are attached to the 2 terminal screws of the switch. The white wires are usually connected to each other but not to the switch itself. This type of connection is typically secured by a nut made of plastic. The ground wires are usually connected to each other and are attached to the switch’s grounding screw.

Steps to Change a Light Switch

If your switch has an on and off labels embossed on its body, and it’s the only switch that controls lights, that means it is a single-pole switch. These are the steps to change this kind of switch.

  • Turn Off Power

    First, make sure that you turn off the power to the circuit at the circuit breaker. This is also called the fuse box. If you want to check that it was successfully turn off, you can flip the switch to see if it will operate a light. You can also use a voltage tester once the switch plate is removed and this way, you can confirm that the wires are not charged. Do not attempt to change a light switch without turning off the power because it could be dangerous.

  • Remove the Switch Plate

    When you’re sure that the power is off at the circuit breaker, you can remove the switch plate and the existing switch. To do this, use a flathead screwdriver. Remove the switch cover with the flathead then use a Phillips screw to remove the existing switch from the box.

  • Remove the Wires

    Now that you’ve removed the plate and the existing switch, you can remove the wires from the old switch to change a light switch. You would need to use the screwdriver again. Loosen the screws that are holding the wires on the sides of the switch with the screwdriver. Once they are loose, disconnect the wires from the switch itself.

    In this step, it’s important to observe the colors of the wires and where they had been attached to the old switch because you will be repeating this placement when you install the new switch. If you’re having difficulty working in the small space, you can use a needle nose pliers. Separate the wires by bending them to the opposite corners of the box. If the switch has green wires or grounding wires, remove them last.

  • Attach the Dimmer Switch

    This step involves three wires. There will be one black wire, one white wire, and a separate ground wire which is sometimes wrapped in green or bare copper. Check the wires’ quality and if any of them seem weak, trim it and re-strip the end.

    Identify the 3 different colored wires and attach the new light switch according to the same pattern when you removed the old one. If your wires are solid copper, you need to make a loop at the end of the wire using pliers. Wrap it around the screw on the side of the switch. Make sure to tighten the screw to ensure that the wire is properly held beneath.

  • Attach the Switch

    Finally, you can attach the switch to the box and reinstall the switch plate. Make sure that the wires are properly attached. If there is any excess wire, you can gently fold them and compress the dimmer switch into the electrical box. Be careful not to loosen or break the wires. Tighten the screws to the switch box and fit the new plate.