The medium Henry Slade was caught in fraud many times throughout his career. In a séance in 1876 in London Ray Lankester and Bryan Donkin snatched his slate before the "spirit" message was supposed to be written, and found the writing already there. Slade also played an accordion with one hand under the table and claimed spirits would play it. The magician Chung Ling Soo revealed how Slade had performed the trick.
During the séance or trance period, note that as a medium you should not ask too many questions of the person you are helping. A good medium never asks the client to tell them the name of the deceased or any details; otherwise, it is not a valid reading. It is up to you to validate the deceased loved one's name, occupation in life, birth date, physical description, how they passed, and so on. https://drive.google.com/file/d/1oKIb0lvlgmr6SMvRUtAUQtqd-xBdUkm_/view?usp=sharing
In 1991, Wendy Grossman in the New Scientist criticized the parapsychologist Stephen E. Braude for ignoring evidence of fraud in mediumship. According to Grossman "[Braude] accuses sceptics of ignoring the evidence he believes is solid, but himself ignores evidence that does not suit him. If a medium was caught cheating on some occasions, he says, the rest of that medium's phenomena were still genuine." Grossman came to the conclusion that Braude did not do proper research on the subject and should study "the art of conjuring." https://drive.google.com/file/d/1FQpaQ5Yg1C3zQMTeg0JudS53TaLVGdqN/view?usp=sharing
Humans have been fascinated with contacting the dead since the beginning of human existence. Cave paintings by indigenous Australians date back 28,000 years, some depicting skulls, bones, spirits and the afterlife. Other cave paintings in Indonesia date back a further 10,000 years. Mediumship gained popularity during the nineteenth century, when ouija boards were used by the upper classes as a source of entertainment. Investigations during this period revealed widespread fraud—with some practitioners employing techniques used by stage magicians—and the practice began to lose credibility. Fraud is still rife in the medium/psychic industry, with cases of deception and trickery being discovered to this day.