Brilliant hubby is shining so brightly with this low tech solution for locating wood studs. We were trying to hang a new shelf last week and couldn't find our stud finder. He took a stack of magnets and moved them slowly across the wall until they stuck to the wall. The magnets were attracted to the screws that are holding up our drywall, which are located on the studs.
Ouch, my eyes are hurting from his brilliant rays, I better go put on sunglasses!