On a run to the local home center I was talking to the clerk about the weird posts we sometimes get here but he came up with the topper.
A guy came in and wanted to see a stud finder. The clerk showed him one and the guy ask if he could try it. The clerk said "Sure." so the guy put it on his arm. The clerk asked what he was doing and the guy said that he had broken off a drill bit in his arm a couple of years ago and he just wanted to see if it was still in there so he could get a tetanus shot. It was.