Help Oneself Puns

You can't make this up: trying to hang a mirror and shelves for my 2 year old's room. He's "helping". We pull out the studfinder to see where to drill. It took everything but i resisted the urge to make the obligatory dad joke about testing it on oneself, i figure he's too young to get the joke anyways. Studfinder is broken. O well, we look for it by tapping and we find the stud, and hang the mirror. My son continues to play with the studfinder the rest of the day. A few hours later, he comes up to me and starts rubbing it on my back. And the studfinder that was broken all day suddenly starts working.

Apparently it just needed calibrated.