You can't disprove those things. People who believe in ghosts or fairies or angels or gods always beliefs plus claims of evidence. You can disprove some part of the evidence, but they'll always have another bit of evidence where there's not enough data to prove anything one way or the other.

It's the same deal with space aliens visiting Earth. The evidentiary basis for that is no stronger than that for aliens. You're correct that it's preference that leads some to favor aliens over angels, etc. But that's all it is.