Well, it's hard to say for sure. Sometimes stories like Maxine might be based on real events but with fictional elements added. Or it could be completely made up. We need more details to determine its authenticity.
Not really. Maxine is mostly a fictional creation with elements that might draw inspiration from various sources but not a direct retelling of a true event.
I don't think they are real. Old hospitals like Barlow Hospital have a lot of history and mystery associated with them. The stories might have started as a way to pass the time or to add an element of excitement. Also, the creaky floors, old equipment, and dimly lit corridors can make people imagine things that aren't really there.