How do I safely avoid drilling into wires in a masonry wall? I can't rely on finding studs
The interior walls in my house are all 100% masonry. Almost all of the wiring is in visible surface-mounted conduits (handy). But there are just a couple of walls which have recessed plug sockets and no visible wiring. How do I find out where it's safe to drill in these walls?
I can't rely on a stud finder because there are no studs, the walls are uniformly solid masonry - apart from, presumably, where the live wires are secretly buried. And because they're not hollow walls, I can't just poke a gentle hole through the plasterboard with a screwdriver or something.
I know all the usual stuff, like that the wires are supposed go in straight lines horizontally or vertically from the socket, and sometimes along the top of the walls or the corners, etc. But how do I find out for sure where they *actually* are, without electrocuting myself or burning the house down? #diy source