People put a lot of hope into contact with the dearly departed!
I know this, having been in the spiritualist churches. Members of the congregation, coming to the services only to get a message from their dear deceased spouse, or offspring, or parents:: their sadness was consummate, understandable, and obvious!
So obvious that opportunists have been known to take advantage of them.
My thought is that there be opportunists on the "other side" as well! These might be the ones coming through as EVP.