In 1910 at a séance in Grenoble, France the apport medium Charles Bailey produced two live birds in the séance room. Bailey was unaware that the dealer he had bought the birds from was present in the séance and he was exposed as a fraud. The psychical researcher Eric Dingwall observed the medium Bert Reese in New York and claimed to have discovered his billet reading tricks. The most detailed account at exposing his tricks (with diagrams) was by the magician Theodore Annemann. https://drive.google.com/file/d/1NC_exEwvIecJ9EWDa-MwzzZdzPkWWZ-H/view?usp=sharing
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
The Austrian medium Rudi Schneider was investigated in 1924 by the physicists Stefan Meyer and Karl Przibram. They caught Rudi freeing his arm in a series of séances. Rudi claimed he could levitate objects but according to Harry Price a photograph taken on April 28, 1932 showed that Rudi had managed to free his arm to move a handkerchief from the table. According to Warren Jay Vinton, Schneider was an expert at freeing himself from control in the séance room. Oliver Gatty and Theodore Besterman who tested Schneider concluded that in their tests there was "no good evidence that Rudi Schneider possesses supernormal powers."
"Mental mediumship" is communication of spirits with a medium by telepathy. The medium mentally "hears" (clairaudience), "sees" (clairvoyance), and/or feels (clairsentience) messages from spirits. Directly or with the help of a spirit guide, the medium passes the information on to the message's recipient(s). When a medium is doing a "reading" for a particular person, that person is known as the "sitter".
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.