Project Alpha was an elaborate hoax that began in 1979 and ended with its disclosure in 1981. It was orchestrated by the stage magician and skeptic James Randi. It involved planting two fake psychics, Steve Shaw (now better known as Banachek) and Michael Edwards, into a paranormal research project. During the initial stages of the investigation, the researchers came to believe that the pair's psychic powers were real. However, more formal experiments, as well as criticism from both the parapsychology community and Randi himself, led them to dismiss their initial trust.[1] The hoax was later revealed publicly.
Following Project Alpha, Randi went on to use variations of the technique on several other occasions. Perhaps the most famous example led to the downfall of TV evangelist and faith healer Peter Popoff, when Randi had a man pose as a woman with uterine cancer, which Popoff happily "cured". In another example, Randi worked with performance artist José Alvarez, who posed as a channeller known as "Carlos", who was presented on Australian TV and soon had a wide following. After this hoax was exposed, the artist was constantly approached by people who believed him to be genuine, even if he told them directly that he was an actor.
I remember this being talked about on TV. Even after his followers were told it was a hoax many thought he was testing them and refused to stop believing he had psyhic powers...so yes, humans are stupid enough to believe people like Sylvia are real