How to Replace an Electrical Switch
Step 1
Turn off the power. Locate your fuse box (usually in a basement or laundry room) and turn off the power to the part of the house you'll be working on. The fuses are generally marked, but if not, it helps to have a second person present to tell you when the power is off in the area you will be working. The easiest way to do this is to plug in or turn on something in the closest outlet to where your switch is located, and then wait for it to be turned off when power is shut off. However, even when you THINK you have the power off, it is a good idea to test the wires BEFORE touching the bare wire within the switch box.
Step 2
Remove the switchplate (the plastic plate that is on the wall) and remove the screws for the mounting yoke (the metal plate that holds the switch).
Step 3
Remove the switch from the box so that you can work on it, and examine the switch for a loose wire, foreign object, or other reason for the malfunction. You should notice that there are two black wires attached to the switch, and two white wires that are tied off (either to each other or seperately) with a wire nut. This is because a switch simply needs to connect or prohibit the current flowing through the black wires, and does not rely on being grounded by the white wires.
Step 4
After making sure that your new switch looks like the old one (where the wires attach), go ahead and remove the wires from the old terminals and place them on the new switch. The new switch may have a different type of attachments (push-in versus screw-on), but this shouldn't matter. If you need additional bare wire to make your connection, strip away a SMALL amount of the black coating. Leaving bare wire sticking out away from the switch increases your chances of later problems, including fire, so should be avoided.
Step 5
Before screwing the new switch back into the switch box, make sure that you have it turned the correct direction (so on is "up" and off is "down"). At this time, you are ready to screw the switch back in and screw the switch plateback to the wall. Before putting your tools away, though, turn the power back on and make sure that your switch is working!
