How to Install an Electrical Switch

Replacing an electrical switch is quick and easy if you follow a few simple guidelines and take the appropriate safety precautions. An electrical switch may be used to turn a light or other appliance on and off. An electrical switch is used to break an electrical circuit, either cutting off the electrical current or allowing it to pass through.

Step 1: Turn off the Power

Before you begin any project that involves electricity, it is important that you turn off the power. Go to the circuit breaker and switch off the power for entire house. Some choose to turn off only the specific fuse they are working with, but turning off the power to the house is the best way to avoid shock or electrocution.

Step 2: Know Your Wires

When replacing an electrical switch there are three different colored wires you will be dealing with: black, white and green/bare. One of the black wires will be the live wire that is always hot, while the other will attach from the switch to the light fixture. The white wires will be connected using a wire nut and the green or bare copper wire will attach to the grounding screw discussed in the next step.

Step 3: Examine Your Switch

When purchasing a two-way switch, you will want to make sure that the switch has two terminal screws on one side and one screw towards the bottom of the other side. The terminal screws on the one side will be hooked up to the black wires, while the green grounding screw on the other side will be hooked up to the green or bare copper wire.

Step 4: Stripping the Wires

Once you have identified all of the wires and know your way around the switch, you are ready to begin. Start by stripping about 1/2 to 5/8 inches of the wire insulation from each insulated wire. You may use either needle nose pliers or a wire stripping tool.

Step 5: Connect the White Wires

Using a wire nut, attach the white wires in the electrical box. Simply place both ends of the wire in the wire nut and screw the nut into place. You can pick up a wire nut at most hardware stores.

Step 6: Hook the Wires

Use needle nose pliers to hook the black and green wires. Grab the top of the wire with the pliers and bend the wire so that it forms a hook.

Step 7: Screw the Wires into Place

The two black wires connect to the two terminal screws on the one side of the switch. Hook each black wire to one of the terminal screws. As you screw the wires into place, the end of the wire will close the loop. Next, screw the green or bare wire to the green grounding screw. Make sure that you turn the wire loop in the same direction as the screw threads.

Step 8: Finishing up

Once the wires are screwed into place, screw the switch into the electrical box and then mount the cover plate over the switch. Restore power and test the switch to make sure it works correctly.