Utility Lock
Anyone who encounters this strange-looking object would have a difficult time trying to figure out where it belongs. The metal thingy appears to have sharp teeth on one end, though that doesn’t help us even the tiniest bit. Like the OP, we’re going to have to seek answers from strangers on the interwebz.
One after the other, online users told the OP that it had all of the characteristics of a utility lock. It’s mainly used to install cables and wires, though only professional technicians would actually know how to use it. Was it only the OP and us who had no idea what this thing was and what it did?