There's a long human history of beliefs like that in spiritualism, animism, etc. People believed they could hear the voices of their dead ancestors, spirits, etc for example.

I wouldn't describe this as "raving", this is someone who has had very real personal experiences. To them, they happened just as much as the sun rises and sets. I don't know what I'm getting at other than have some patience and compassion for people who experience distressing things that they themselves cannot explain.