Here's some fascinating trivia about Houdini, who's real name was Erich Weiss, hungarian Jew.
Interest in seances, contacting the deceased was a major past time in the late 1800's early 1900's which of course were all fraudulent. Houdini's interest in it was ore than just the opportunity for another trick but a genuine interest in the afterlife, fascination with it even existing.
He devised a plan with his wife as an experiment to determine whether or not contact with those who died was possible. The plan was that when he passes away, she would attempt to make contact with him, and having him conveying a secret message kept locked away in a bank vault.
Despite innumerable seances, attempts to have the spirit of Houdini convey the secret message, all attempts failed to contact Houdini after he died failed.