Light sockets come in many shapes and sizes. Most lamps use 120 volts, but some speciality lamps require 240 volts to operate properly. The light socket's purpose is to hold a bulb in place and to provide voltage needed to turn the light on. A wall switch usually controls the light. Three wires connect to the socket. Two are hot wires and one is a ground wire.
Turn off power at the main panel. The breaker supplying the socket is double thick. Single breakers are for 120 volt circuits and double breakers are for 240 volt circuits. Use a volt meter to verify there is no voltage at the socket. If you cannot locate the correct breaker, turn off the main.
Strip the wires back about 1/2-inch on the ends and twist the wire strands together with your fingers. The ground wire is a solid copper wire. It may have green insulation or it may be a bare wire.
Connect the ground wire to the green screw that is located on the socket. Twist the wire around the screw in a clockwise direction. Tighten the screw securely.
Connect the remaining two wires to the two gold coloured terminals on the light socket. If the insulation on one of the wires is coloured white, wrap a piece of black electrical tape around the end near the socket terminal. This is to inform someone working on the fixture in the future that the wire is not a neutral wire and that it is part of a 240 volt circuit.
Turn the power back on and carefully use a meter to confirm that the voltage is correct. Make sure that the wall switch is turned on.
Insert a 240 volt bulb into the socket, to verify that it is working.
If you are not comfortable working with electricity, have the work done by an electrician.
Electricity can cause serious injury or death. Always double check to make sure the power is off before you start working with electrical wires.