Removed two wall sconces that had been mounted on each side of a bathroom mirror to relocate the circuit and mount a centered fixture higher up. The electrical on the left was fine. Look at the one on the right. Person(s) unknown, found that behind the cutout was the vent tube/pvc pipe, and had no room for a proper junction box. Negligence must have kicked in: they secured a metal mount plate to the vent tube via wire. The sconce was basically held in place via friction with the wall. WORSE, the metal plate was not bonded to a ground. NOT to CODE.  No concern for safety.