Before the greys were abducting people, people were claiming to be abducted by other creatures. The greys are apparently just a new type of creature in the abduction phenomenon or folklore or whatever you want to call it.
There are reasons why I am skeptical that we are being visited by extraterrestrials. There are problems associated with traveling great distances. Unless there is some sort of technology that enables folding space or sending a craft through some type of wormhole, the possibility of distant space travel doesn't seem likely to me. I have even read that a craft traveling at speed near the speed of light arriving in our solar system should emit enough energy that our instruments here on Earth should be able to pick up their emissions.
What I find interesting are flying triangles. I believe I actually saw one around dusk about 10 years ago but I couldn't make out the shape. It had a dim triangular light configuration. I made so sound whatsoever. I ran towards it and ran past a nearby tree so it wouldn't block my vision of it only to watch it disappear into the horizon. It was heading northward. Some people like me believe they are antigravity aircraft.