WARNING: Not to be taken too seriously.

In the UFO thread, it was brought up in discussion whether or not "Fairies" are more plausible than extraterrestrial intelligence as an explanation for UFO sightings.

As I have far too much free time, I decided to explore the unlikeliest possibility that the Fae may exist in some form or another.

So what are the qualities of "alien" encounters and fairy stories? Where do they intersect, and where do they differ?

Well, the common tales of both mythos include "abduction" of one sort or another, sometimes with "lost time" displacement. Both types of being are often described similarly as slim, having large heads and eyes, long fingered, and smaller than human average. In many cases they are considered extremely charismatic or mesmerizing.

So, let's speculate. An offshoot of H. Sapiens, with some ability to induce a hypnotic state in human beings? And of course, the ability would need to include a way of altering or disrupting recording and photography. Which suggests an electromagnetic effect. Technology or bioelectricity? You be the judge!

As far as flying lights, a Terrestrial source of air vehicles or gliders is plausible. After all, if aliens can hide their presence from humanity, so can (hypothetically) an Earthly species. Perhaps they have hidden nanotechnology, allowing the creation of metamaterials to cloak their detection? Again, no more implausible than aliens doing it! Any evidence of prior industrial development leading up to nanotech would of course have to have been removed and destroyed before humans could find it. Factories torn down and the grounds scoured for traces of artificial materials.

Impractical, yes. Impossible? Who can say!