So a few years ago I was sitting in a chair in a room and heard a loud POP behind my head. Loud enough pop that I got a headache afterwards. Immediately following the pop, a bunch of pieces of metal clinked onto the floor around the room. Four of them to be exact. I put 3 away and set the other aside (it had the clearest markings). Now I can't find the 4th one so I dug up the other 3.
Thing is, the room was largely empty, and the source of the pop/metal pieces was a complete unknown since I don't see any potential origin for them save one.
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The room is still pretty much the same as it was. There's a vent in the ceiling which is the only thing that could have possibly spat out the metal bits. It never did anything weird before or since though.
Also the pop sounded like it was in the room itself, not the ceiling. Like it was right behind my head, as if a huge person clapped their hands together as hard as they could.
Whatever these things are, somebody should be able to identify them. They're all identical and look like standardized parts. The lettering is actually readable too.
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