Alien Abductions
Many human beings have reported being abducted by non human entities.
This has increased rapidly in the last century. Some of these abductions have been reported as being terrifying whereas others have been described as being a pleasant experience.
The most common type of alien which has been reported are the "Greys". They are called Greys because of their colour. The interesting thing is there have been more "sightings" of these creatures since the release of "Close Encounters of the Third Kind", which featured these aliens in the latter part of the film.
Therefore, could it be suggestion that has caused many people to believe that they have been abducted by these creatures. The one thing which many of these "abductions" have in common, is that they take place when the person is alone either in bed or in an isolated spot.
Many abductees have reported seeing lights in the sky or in the room immediately before the abduction occurs. There is usually no memory of the event and any reports are usually carried out under hypnosis.
Abductees often report being unable to move and being "floated" into a hovering UFO. The most terrifying of these reports, are those which report being "experimented" on.