I'm also beginning to think that UFOs may not necessarily be extraterrestrial. Maybe from another dimension right here on earth, and they pop into our dimension from time to time, either intentionally or occasionally through some odd, accidental quirk of physics. Or maybe they come from a parallel universe. Also could be true of ghosts, shadow people, etc.
Jeez! Can you tell I've been watching too much Travel Channel's Paranormal: Caught on Camera?