Have an unused receptacle in the ceiling that used to have a fan. What is safe way to cap it?
You can leave the ground wire bare, it's fine. As long as the other wires are capped off so that no bare metal is exposed, then those are fine, too. You can bend the wires and stuff them all into the box, then put a blank faceplate on the box. You cannot cover the box with sheetrock or anything. You have to leave it accessible.