This gfci wiring provides protection to a duplex receptacle. By connecting the load terminals on the last gfci, the receptacle is protected and can be used just as if it were one of the gfci receptacles. One ground fault circuit interrupter at the beginning of the circuit can be used in the same way to protect multiple, subsequent receptacles as illustrated in the diagram below.
In these cases, it should be wrapped with electrical tape to mark it as hot. The ground wires will be green and/or bare copper. The ground should be spliced with a short piece of wire and connected to each device and outlet box that has a grounding terminal. In these drawing the brass colored terminal represent the hot side of the device and the silver colored terminal represent the neutral. Ground wires and terminals are in green.
Use this wiring when the source is at the fixture and you want to control the feed to both components with the same switch. Three-wire cable runs from the fan to the switch box and the source neutral is spliced to the white wire and to the fan neutral.
This ground fault circuit interrupter wiring diagram of the same device leaves the switch out of the protected circuit. With this arrangement the receptacle is protected but the switch remains outside the circuit. This arrangement can be used to control a light or other device where the extra protection of a gfci is not necessary.