This page contains wiring diagrams for adding a new light fixture using an existing receptacle as the source. Diagrams include adding a light from a switched receptacle and tapping an always-hot outlet. Different wiring arrangements are included to allow for either the light or the switch to come first in the circuit.
This diagram illustrates some of the most common circuits found in a typical 200 amp circuit breaker box. The breakers are installed in a service panel so that contact is made with one of two hot bus bars that run down the middle of the box. The hot wire for a circuit is connected to the breaker by a set screw on the base.
Another, more permanent, repair for an old doorbell circuit is to use a small ac adapter in place of the battery. Most people will have an AC adapter left after an old radio or similar device has long since died. Look for an output of 10 to 16 volts printed on the side of the adapter casing. Current ratings will typically be very low from these adapters, around 500mA, making them perfect to power the doorbell circuit. All that is needed is a conveniently located receptacle to plug the adapter in.
These sockets have two terminals, one for the hot wire and one for the neutral. A third contact may be present but is not used for this circuit. This diagram illustrates wiring for a standard, one setting lamp. This socket has two terminals, the brass for hot and the silver for the neutral wire.