Q: I need to install shelves in various rooms. I was given a stud finder to help determine the best places to hang the shelves. For the life of me, I can’t figure out how to use it! Any advice?

How do I use a stud sensor to find the best place to hang shelves? Locating studs — the vertical framing in a wall — is essential if you are trying to hang shelves, cabinets or other heavy items.

Many stud sensors also have metal and live-wire detectors. Most sensors need to calibrate to the wall so they can signal density changes. Place the device flat against the wall, press down on the ...