/diy/ - Do It Yourself

Quick question: Does anyone know what these are?

A friend of a friend found these inside a wall at home, brought them to a hardware store and somebody told her that they look like spy devices. She feels very distressed by this and seems to have a predisposition to paranoid thinking. I don't know what they are, but I'm doubtful that they are spy devices. I was just hoping maybe someone here could identify them.

Sorry for the non-DIYish post.