I have a single gang box in a bathroom with a GFCI outlet. I'd like to replace it with a 2-gang box containing a GFCI outlet and a light switch for the vanity light. The outlet will have both receptacles live (not switched).
The vanity light currently is not switched; it is controlled by a pull-chain on the light itself. We're going to replace it with a non-pull-chain type of light and we want a switch where the kids can reach. It'll be nice not to have to explain to our guests how to use our bathroom, too.
I did some poking around and it looks like the vanity light is fed from a different branch from the receptacle.
One plan is to pigtail the switch and gfci outlet onto the supply line, and then take the output of the switch out of the box up to the vanity light.
Another way to do it would be to run a switch loop from the lighting fixture down into the 2-gang. The gfci receptacle would be wired the same as it is now, and the switch would be on the switch loop.
Is one of these the correct way to do it? If not, how should I wire this?