Turn off the circuit breaker to the switch you are replacing. Circuit breakers, located inside your electrical box, will control all power to one side of a room or an entire room.
Remove the two screws that secure the cover plate to the wall. Remove the screws that attach the light switch assembly to the junction box. The switch is the same whether in a manufactured home or a standard foundational house.
Pull the switch away from the junction box, but do not touch the wires. Place one probe of the circuit tester to the metal junction box and then place the other probe on one of the wire terminals on the switch. If the tester lights up, there is still power going to the switch. Turn off the correct circuit breaker and test the switch again. When the tester no longer lights, there is no power going to the switch.
Loosen the two terminal screws that secure the black and white wires to the switch.
Cut off the bare end of each wire and remove ¼-inch of insulation with the wire stripper. This will ensure that you have good contact when installing the new switch.
Connect the wires to the terminals of the new light switch. Bend the bare ends of each wire clockwise around its respective terminal screw. The black wire attaches to the negative terminal, which is usually made of brass. The white wire connects to the positive terminal. Tighten screws onto the wires, securing them to the switch.
Position the new switch in the junction box and secure it with the two retaining screws. Replace the switch cover and restore power to the circuit.