The other wire black takes the power back to the light box and is connected to the light itself.
Light switch and receptacle in same box.
It is connected to the wire bring power to the light box.
Notice that these outlets have the tab removed from the hot side or brass side of the outlet which allows the top half of the plug to be controlled only from the switch.
I d like to replace it with a 2 gang box containing a gfci outlet and a light switch for the vanity light.
It depends how you want the switch and receptacle to function.
Wiring a light switch and outlet on the same circuit is something that electricians do regularly.
Buy a single pole switch if one switch controls the lights or a three way if you have two switches controlling the same lights.
A few fluorescent lights can be dimmed with special dimmer switches but most can t.
In this situation you need 3 wires between the light and the switch box to have an outlet next to the switch.
The red and black are used for hot and the white neutral wire at the switch box allows for powering a timer remote control or other programmable switch.
If you want the receptacle to be powered all the time and want to use the switch to control a load other than the receptacle such as a light fixture you wire it like this.
One wire white brings power from the light box to the switch.
The vanity light currently is not switched.
This is an updated version of the first arrangement.
I have a single gang box in a bathroom with a gfci outlet.
Jul 30 2017 easy to read diagrams for two outlets in one box 2 switches in one box switch and outlet in same box and other 2 gang wiring.
Wiring a switch and outlet in the same box.
Standard and halogen bulbs require standard incandescent dimmers.
The first thing you need to do is distinguish the line cable coming from the panel from the load cable which is the one going to the light fixture.
Because the electrical code as of the 2011 nec update requires a neutral wire in most new switch boxes a 3 wire cable runs between the light and switch.
If power is coming into the switch box from the panel and you want to connect an outlet to the switch your first option is to wire the receptacle to always be on.
The outlet will have both receptacles live not switched.
Both devices are spliced to the same hot source.
It is controlled by a pull chain on the light itself.
They often run wires from the switch to a remote outlet but there s no reason why the switch and outlet can t be in the same electrical box.