A friend of mine went to such a medium who was giving a demonstration on some newagy convention. You know, the thing where all those little old wives do card and aura reading and sell you things that others throw into the garbage.
At one point he got her attention and told her about his company being into problems, his personal problems and stuff about his father that died recently. That ain't making it difficult for a cold reader so she starts her mombo jumbo about she feeling his father and him, through her, giving advice to his unhappy son, yadayadayada, the whole sideshow.
Then she asks if he is happy with the message and to her surprise he says no.
He tells her his father is pretty alive, he doesn't even own a company and has no personal shit. He just made everything up.
So, she was just pulling shit out of her ass. He had to leave her demonstration but not before having exposed her as a fraud to most of the audience. Some keep believing, no matter what.
So if you really wanna know, go to a demonstration or whatever and act like the victim they look for to fool the masses and play along. After (s)he took the bait, reveal the truth.