In a previous life I was a magician and had magical friends, as it were. One of my friends, who was well versed in deceptive techniques like cold reading, sleight of hand, spirit writing and such-like, was persuaded to attend a seance. He went, intending to have a good laugh.
He came out scared.
He would rarely talk about it, but AIUI his problem was that not only did the voice of the medium change, but her face did. She "became" someone else. He did not have a conjuring explanation for it and it really shook him.
He never went again.
I have another friend who is lovely, but her father is a bullying PITA. Big man, used o getting his own way. One day he went into a pub, sat down in a corner with his pint and laughed as he saw a woman in a crinoline dress walk into the room and out into the next room. He followed and there was no-one there. He asked the barman what was going on with the fancy-dress party. What FD party? He explained. Oh that will be Alice, she regularly visits.
Both men were serious.
Of course, both these stories were second-hand to me, but I have no reason to doubt the sincerity of the raconteurs.
It's getting late, but don't have nightmares.
Boo.