http://www.usatoday.com/news/offbeat...il-skull_x.htm

LITTLETON, Colo. (AP) ‹ A dentist found the source of the toothache Patrick
Lawler was complaining about on the roof of his mouth: a four-inch nail the
construction worker had unknowingly embedded in his skull six days earlier.


It doesn't actually say that he'd taped the trigger, but blamed the accident
on a "backfire".