I haven't come across any evidence that would convince me that extraterrestrials (or ultraterrestrials, for that matter) have visited Earth in historic times, but there is a surprising overlap with #folklore .
Night hags/sleep paralysis demons are the most obvious example, but there are numerous other weird phenomena in old folk tales that would pass as " #UFO lore" nowadays. Fiery spheres or streaks in the sky, weird substances dropping down from up high, and so on and so forth. I might even write a book of folk tales about such "Fortean Phenomena" one day, if I find the time - I certainly have enough source material to work with!
