Before working on any circuit in your house, make sure you turn the light off at the circuit breaker and then test it at the switch. Use 14-2 wire which has two insulated wires, a white and a black, and a bare copper wire which is used for grounding. First you run a 14-2 wire from the main circuit panel into the switch box. Then run a 14-2 wire from the switch to the light bulb. The black wire from the main circuit panel gets attached to one of the poles on the switch. The black from the 14-2 that goes to the light bulb goes on the other pole of the switch. The whites from main circuit wire and the wire going to the light bulb get twisted together and wire nutted. The bare copper wires get twisted together and attached to the green lug nut on the switch. At the fixture the black wire goes to one contact and the white wire goes to the other contact. The bare wire would normally be attached to the chassis of the light fixture. This is a very simple item to wire.