Some years ago, I briefly studied Carl Jung's ideas of "archetypes" and the "collective unconsious". People who believe in the supernatural are at a place in their lives where they are "needing" to engage with this primitive part of the psyche. The majority of people only interact with this through their dreams. And modern people often cannot even remember their dreams.
It is important to be clear that any "messages" that come through should not be taken on a literal level. These messages are for making sense of the "inner landscape" of the individual psyche. These are the elements, motifs, and archetypes of art and the creative forces of the psyche interacting with the realm of emotions, passions, and unconscious repressed desires. The psyche strives for coherence and "wholeness".
We can dance with these "archetypal symbols" to enhance creativity in life. But some people might take it all too literally, somehow believing that what is "mythic" in the inner worlds, is also true in the out physical/material world...as in the above stories shared by Matt . (And then people with mental disorders of schizophrenia cannot manage any of this properly unless they can get modern medical treatment...it is as if they are dreaming while awake).
This is not my first go around with people like this, I’ve met people have claimed that they see ghosts, angels, spiritual guides etc. I just didn’t know this particular person believed it.
I would either decide to "enjoy" their stories...listen and say: "hmmm, that's interesting"...or decide to move on...because you won't be able to talk anyone out of these beliefs, they have to do it on their own. And I would simply say: "I have a different belief. I believe in a materialist, scientific understanding of things."
If I add the “internet” crowd to this number of detached people that believe in lizard people, deep underground bases and other “fringe” ideas and those people are those that are not using the canon as the standard of truth, the number of detached people would exponentially multiply.
I wonder what Carl Jung would have to say about this, if he were alive. As these are the mythological elements that could haunt peoples dreams.
As for approaching it from science: this book might be relevant: The Demon-Haunted World: Science as a Candle in the Dark by Carl Sagan.