Well-known UFO writers Jacques Vallee and John Keel both came to the conclusion that UFOs were paranormal in origin, NOT physical spacecraft from here or anywhere else. They can have effects in the physical world, but they do not originate in the physical world. Christian students of the phenomenon have reached similar conclusions. ALL of these writers believe that deception is one of the primary attributes of the phenomenon.
Of course, at this point we have no way of knowing if something perceived as physical is indeed physical or do our brains (including our unconscious minds) only interpret it as physical when it is actually either not physical or, at least, not physical in this dimension/reality.
Perhaps some kind of a hologram? - Tom
Bingo! J. Allen Hynek reached the same conclusion. Many or all of the various paranormal phenomena are often reported occurring at the same time in the same location. In the case of the Skinwalker Ranch in Utah, the research team that camped out there witnessed everything from UFOs to Bigfoot to poltergeists, etc.
I am convinced that these phenomena are just different manifestations of demonic influence.