Most of the Fremantle Asylum ghost stories are probably a mix of real - life elements and pure legend. The asylum had a reputation for being a harsh place. Deaths and difficult situations were common. People tend to look for explanations for strange feelings or noises in such spooky old buildings. So they create ghost stories that incorporate the real history of the place, but whether they are based on real supernatural events is highly doubtful.
It's hard to say for sure. The asylum was a place full of pain and misery. There were likely many unexplained happenings during its operation that people didn't understand at the time. These could have been the basis for the ghost stories. However, from a scientific perspective, there's no proof that ghosts exist. So while the events that inspired the stories might have been real in some sense, the idea of actual ghosts is more of a superstition.
Some might be based on real events in a distorted way. The Fremantle Asylum had a difficult past with many patients suffering and some staff facing hardships. Over time, these real - life tragedies could have been embellished and turned into ghost stories. But there's no concrete evidence to prove that the ghosts are real.