In our daily life, we will definitely encounter the situation that the light switch does not work. If the light switch does not work, it should be replaced. Most best modern light switches have screw terminals on each side, and there may be holes in the back to accommodate the end of the wire. Although plug-in connections may be more convenient, they are less reliable than those with threaded terminals, so do not use them!
You can easily loosen the screws on the side of the device using a standard screwdriver (turn counter clockwise), but you may find it difficult to remove the wires from the back of the device. To remove the wires, insert the blade of a small screwdriver into the slot under the hole where the wires are inserted and push in when loosening the wires. Push the screwdriver blade into the slot and release the handle on the inserted wire. Here is a description of these wires and where they are going:
Connect the white (neutral) wire to the silver screw or place it in the back wire hole on the same side of the device as the silver screw.
The black (hot) wire is attached to the brass screw or to the hole in the back of the unit on the same side as the brass screw. This wire is sometimes red.
The green or bare copper (ground) conductor (if the equipment has one) is connected to the green screw terminal or electrical box on the switch.
If the main body of the switch has a switch stamp, and it is the only switch to control the light or socket, then it is a single pole switch. To replace these switches, perform the following steps:
Turn off the power to the switches on the main circuit breaker or fuse panel.
Unscrew and remove the switch board; then use the voltage tester to make sure the circuit is de energized.
Unscrew the switch from the electrical box and pull it off while the wires are still connected.
Compare the new switch to the switch that you are replacing in order to find the appropriate location for the electrical screw connector.
Connect the first wire that was removed to a screw of the same color as the old switch on the new switch; do the same for the second wire.
Gently push the new wired switch back into the electrical box and screw it into place.
Screw on the switch board and turn on the power.