This diagram illustrates wiring a GFCI receptacle and light switch in the same outlet box, a common arrangement in a bathroom with limited space. The hot source is spliced to the LINE terminal on the receptacle and to the bottom terminal on the light switch. The neutral and ground wires are spliced together and run to each device in the circuit.
Use this wiring when the power source originates at the switch and you want to control both the fan and light from there. The hot source is connected directly to the bottom terminal on the switch. Two-wire cable runs from there to the ceiling fan.
This page contains wiring diagrams for ground fault circuit interrupter (gfci) receptacles. Included are diagrams for multiple gfci’s, a protected standard duplex receptacle, and a protected light fixture. Wiring for a switch and gfci receptacle in the same box is also shown to protect the switch and light or to protect other receptacles in the circuit. To wire a gfci circuit breaker see this link and wire a gfci switch combo at this link.
This wiring arrangement allows for lowering the lights with a dimmer and controlling the fan with the builtin pull chain. The source is at the ceiling outlet box and 3-wire cable runs from there to the switch box. The neutral from the source is spliced directly to the white wire on the fan kit and the cable, running it through to the switch box.