Electrical switches usually last a long time, but they do
wear out, or fail. Replacing a household switch is not hard, in most cases. Of
course there are some very important safety precautions to observe, primarily,
make sure the power to the switch has been turned off before attempting any
repairs. Find the circuit breaker, or fuse for older systems, that controls the
power to the faulty switch and turn it off. If it is a fuse, remove it.
Removing a switch:
Once you are absolutely certain the power to the switch is
off, unscrew the face plate that surrounds the switch and remove it. You will
find another pair of screws underneath the faceplate, usually one at the top of
the switch and one at the bottom. When you remove these screws the switch will
be free for you to pull out of the wall. There are some wires attached to the
side(s) switch. These are held on by either a screw or, less often, by a spring
clamp.
The switch may have both side terminals and holes in the
back for what is called back-wiring. In back-wiring the wires are connected to
the back of the switch, rather than the side(s). Regardless of whether the
wires attach to the side or the back, the attachment point is called a
terminal. Use a test light, available at most hardware stores, to make sure
there is no electricity flowing through the wires to the terminals. Touch the
test light's probes to each terminal. If the tester lights up, stop immediately
and go and find the correct circuit breaker and turn it off, or remove the
correct fuse. Then test again.
If the test light does not light up, you may assume it is
safe to proceed. To remove the switch entirely you must loosen the terminal
screws holding the wires and carefully pull the wires off. It is best to do
this one terminal at a time and not allow the bare ends of the wires touch each
other.