I expect my Mum has thrown it away, but I had a Pan Am Junior Pilot badge - a very small pair of wings I think, that had a very sharp pin on the back, which was all of 1.5" long. It'd be confiscated at security, now of course.
Far, far worse was the handle and top of an exploded hand grenade that I picked up in the French Alps in the 70s, left over from WW2. Came back with that in my case....