Scripture proofs or examples to show believers of demon and alien visitations?

[Free Christian]

Hi everyone. I was wondering as a sort of follow up to the last thread/questions I had, a couple of things.
What scripture passages would one point a person to, a person who believed that these things can appear for real, to show them that what they think they see they have not? That demons, Satan, you all know what I mean, can cause an illusion.
I cannot think of any myself.