The hot source is spliced to the black, fan wire and the black wire running to the dimmer. At the other end, the black cable wire is spliced to one of the hot dimmer wires, it doesn’t matter which one. The other dimmer wire is spliced to the red wire in the switch box which is spliced to the blue, light wire at the other end.
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.
This diagram illustrates the wiring for a circuit with gfci receptacles followed by a light and switch. By connecting the switch to the load terminals on the gfci, the light is protected against ground faults as well.
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.