Gyzyk was born in the village of Rączna, near Kraków. He claimed to be able to materialize spirits, produce ectoplasm and levitate objects. Guzyk was endorsed by the psychical researcher Gustav Geley who attended his séances. However, the skeptical investigator Paul Heuzé and a professional illusionist known as Professor Dicksonn suspected that Geley and other psychical researchers had been duped by trickery.
Heuzé organized five scientists, including the French physicist Paul Langevin to observe Gyzyk during his séances. Objects were moved but only in close reach of the medium. They concluded that he had freed one of his legs to perform the phenomena. When tighter controls were introduced, nothing happened.
In 1923 he was exposed as a fraud in a series of séances in Sorbonne in Paris. Guzyk would use his elbows and legs to move objects around the room and touch the sitters. He was caught cheating by the psychical researcher Harry Price. According to Price the "man was clever, especially with his feet, which were almost as useful to him as his hands in producing phenomena." Price also noted that Gyzyk impersonated a "spirit" animal during a séance by placing his hand in a stocking to stimulate the illusion of a snapping jaw.
The psychologist Max Dessoir wrote that the trick of Guzyk was to use his "foot for psychic touches and sounds". He was investigated many times and his mediumship was detected in fraud. At a séance in Kraków in December 1924 a photograph showed him moving a curtain with his hand. Walter Franklin Prince who attended séances with Guzyk came to the conclusion he had no paranormal ability. The psychical researcher Paul Tabori has written that it was established beyond doubt that Gyzyk had cheated at his séances.
- Jan Guzyk (1875-1928)
- M. Brady Brower. (2010). Unruly Spirits: The Science of Psychic Phenomena in Modern France. University of Illinois Press. pp. 133-135. ISBN 978-0252077517
- Sofie Lachapelle. (2011). Investigating the Supernatural: From Spiritism and Occultism to Psychical Research and Metapsychics in France, 1853-1931. Johns Hopkins University Press. p. 131. ISBN 978-1421400136
- Harry Price. (1942). Search for Truth: My Life for Psychical Research. Collins p. 206
- Paul Tabori. (1974). Harry Price: The Biography of a Ghosthunter. Sphere Books. pp. 118-119. ISBN 0-7221-8326-7
- Lewis Spence. (2003). Encyclopedia of Occultism & Parapsychology. Kessinger Publishing. p. 399. ISBN 978-0766128156
- Richard Cavendish. (1971). Man, Myth & Magic: An Illustrated Encyclopedia of the Supernatural. Volume 6. Purnell. p. 2277. ISBN 978-0863070419
- Arthur Berger. (1988). Lives and Letters in American Parapsychology: A Biographical History, 1850-1987. McFarland & Company. p. 95. ISBN 978-0899503455