How to Replace a Light Switch in Your Home
Changing a switch is a very simple process that does not require a high level of technical skill nor does it involve any highly technical or expensive tools. There are only a couple of things a person must know before starting the process and only four simple hand-tools needed.
For tools you will need a flat screwdriver, Phillips screwdriver and a pair of wire strippers. The flat screwdriver will be used to remove the screw holding the cover plate over the switch. The Phillips screwdriver or the flat tip will be used to remove the screws holding the switch into the junction box. Normally the Phillips screwdriver will be used to loosen the screws holding the wires in place on the switch. Sometimes it is necessary to cut the wires from the switch. This is why you need to have some wire cutter/strippers. You will also need a simple voltage tester available from your local hardware store for about ten dollars. This is used to make sure the circuit is not energized when you attempt to remove the switch.
Before attempting to replace the switch in question you will need to turn the power off so as not to get shocked. Go to the panel box and turn off the breaker or remove the fuse that controls this circuit. Go to the switch and take your tester and place one of the leads on the bottom black wire and touch it to ground. It should show no voltage. Now take the tester and touch it to the top black wire and to ground. If it shows no voltage then the circuit is off. If there is voltage recheck your breakers until you find the proper breaker to disengage power to the circuit.
The next thing you will need to know is the type of switch you are replacing. Most switches found in a house are of the toggle style or regular flip switches. There are designer switches available that have different plates on front to switch but they all wire the same. The main difference is whether you have a single pole, three-way switch, or four pole switch. The difference here is easily found.
If the switch you are replacing is the only switch to turn the light on or off then it is a single pole switch. A single pole switch is the easiest to replace as it only has two wires attached to it. It will only have two or three wires attached to it. The front of the switch will be marked “ON” and “OFF”. This is the only switch that is marked on and off as the others will be in a position dependant on which switch is used.
If you have a single pole switch it will have only two wires and a ground attached to it. The ground always connects to the green screw. The other two wires will both be black or one could be white with a black stripe. The solid black wire goes on the brass screw and the remaining wire connects to the other screw. Now reinstall your switch and turn the power on and you should be set.
If the switch you are replacing is one of only two places to turn a light on it is referred to as a three-way switch. It wires much the same. When you remove the switch from the wall you will notice one of the screw terminals will be marked “COM” for common. This wire must go to the one marked common on the new switch. Of course, it is understood the ground will go to the green screw. The two remaining wires are referred to as travelers. It does not matter which of these wires goes to the remaining screw. The switch will work either way. You will notice there is no “On” or “OFF” marking on this switch. This is because it depends on which switch you use to turn the light on and off as to what position it is in.
If the switch you are replacing controls a light that is turned on at three or more location then you will have to remove the switch to see what type it is.. It could be a three-way or four -way. If it is a three-way just replace it as above. If it is a four way it will have terminals for four wires and maybe a ground. If it is a four-way switch you just need to remember to pair the wires the way they are on the old switch. There should be two red wires and two black wires. You should notice a red and black at the top of the switch and a red and black at the bottom of the switch. These wires need to be paired the same way. What this means is that the two wires at the top should go to the top of the other switch. The other two should go to the bottom. There is no top and bottom to the switch this was just an illustration. If you turn the power back on and your light comes on and when you turn it off you find one of the three-way switches on the circuit does not work just switch two of the wires on the same side of the four-way switch and everything will be fine.
Remember to be safe with electricity it does “KILL.” If you are in doubt ask your salesperson at the hardware store for any advice and they will be happy to help. Be sure you connect all the wires tightly with the screws because this could cause premature failure of your new switch or could cause your circuit breaker to trip. Make sure the wires are not touching one another when you reinstall and everything will be fine.
