My Godfather was "someone important" in the RAF in the late 60's/early 70s and living the life of Riley in a forces-supplied home (think Georgian mansion!), with a small support staff.
One morning a package turned up with what looked like a small black wire poking out of it....
Cue bomb-squad's immediate arrival, evacuation of said building, a very nerve-testing movement of the suspect package out of the building, followed by some impromptu garden re-modelling.
When the dust settled the remnants were inspected....
It was a hairbrush.
Obviously, this being the RAF, the offending item was immediately mounted in a lovely wooden and glass frame and decorated his office for the rest of his life. :D
Turns out the hairbrush was actually a joke gift sent by a friend and was just not very well wrapped!
(they obviously didn't use a huge amount of plastique to "detonate" the package because the wooden body still had a fair few bristles still embedded in it. I remember repeatedly chuckling about it whenever the story was told)