adding a GFI outlet to an existing switch

[miziko]

Hello all,

New member here. I want to add a GFI outlet outside next to a switch, which control an external light. I have purchase supplies already (2 gang box, pipe, all weather cover, GFI outlet, new switch). I have done wiring in the past, but a little fuzzy on these details. What I want to do is plug a fountain into the outlet and still be able to turn on and off the light without affecting the fountain. I would like the light to be protected by GFI as well, as there is an outlet on the pole. If I recall the wires going into the current box are black, white and green. Any details and diagrams would be great and much appreciated.

Thanks for your help!!

[HayZee518]

gfci with downfeed protection

follow this diagram - your light pole will be protected off the gfci

[wmlbrn]

i am wanting to add a gfi to my bathroom. The house is 50 + years old and has no grounds. Any suggestions?

[HayZee518]

is there an existing outlet in the bathroom now? if yes, just replace the outlet with a gfci. if not then you'll need a plastic old work box, a length of 12/2 cable, a standard 20 amp screw in fuse, one romex connector. in the main box right below the two pullouts are where your branch circuits are located. find an empty socket. right below the socket is a screw. the black wire goes here. both the bare and white neutral goes to the neutral bar. the black goes to the odd colored screw on the gfci, the white on the nickel colored screw and the green on the green screw.