This thing is in the garage and the attic of the townhouse we are selling. The RE agent who owns a townhouse in the same neighborhood (rents it out) has no idea what it is either. It is mounted on a crossbeam in the garage and a crossbeam in the attic. It appears to have a small horn behind the left-hand flap. It is about 10" long and 10" across. There is no wiring or batteries. The middle contains a metal wheel that can be spun. I did a Google image search but had no luck. Any ideas??