It's an idea that's been kicked around a fair bit. Taking the principle that people relate what they see to their own environment and perspective, it can be argued that in times past odd things flying about (and odd goblin type things coming out of them) would be just that - fairies or goblins. In our science fiction saturated age, the very same thing is more likely to be interpreted as a UFO and an alien respectively: likewise in the past fairies, hags, incubi and succubi came into people's bedrooms while they slept and stole them away, or in the latter two cases impregnated their victim or stole their sperm: in our time the same phenomenon would be interpreted as greys abducting people. Fairy ring or UFO landing site?
Personally, I tend towards the notion that this serves to mitigate the argument that abductions in particular are basically a psycho/sociological phenomenon: a common, in my opinion purely psychological condition interpreted within the cultural confines of our own society. As to what UFOs are, who knows? (Hint - don't trust anyone who claims they know exactly what they are
).
By the way, Ivan Sanderson, the great cryptozoologist, suggested that UFOs may even be lifeforms of their own accord (which seems to be the current flavour vis-a-vis rods).
