I want to add an electrical outlet to my basement. There is already an electrical box attached to one of the floor/ceiling joists with a wire going in. No wire coming out.
Inside is one set of wires (1 white, 1 black, 1 ground/bare). I have not tested to see if this is live yet. It has the word "post" written on the cover. What does this mean, and is it safe to add an electrical outlet to this box?