comments:
It's a ceiling speaker, probably for background music, or maybe for the rear channel surround speakers if there's a pair along one side of the room. It connects to an amp and sound source, which could be a bluetooth receiver (the kind that you can plug headphones into). Don't expect great sound quality though. Think of what the music in the grocery store sounds like. If you want to use them but can't find the wires and have some cash to burn, you can buy a wiring tracer that will work from a few feet away. Pop the speaker cover off, attach the emitter to the wires, then use the probe to trace the wiring. The ones I have were for piping music through my house. Found the wires ended behind an electrical outlet cover where I assume the entertainment system used to be.