My house is roughly half a century old and the two bathrooms share a common wall. Along this common wall in the bathroom I am remodeling is the shower stall. After taking down the tile I realized the light swith electrical box to the other bathroom is behind the tile of my shower stall, def. a building violation now days. I really don't want to mess with it. I have no fear of it getting wet at all but I don't like it touching sheetrock so I put a barrier of aluminum foil, then roofing paper then drywall. Is wrapping the exteriror of an electrical box with alum. foil bad? I couldn't think of any issues. In my mind I saw it as a barrier between a spark lighting the roofing paper on fire. Any thoughts?