Well, it's not a straightforward yes or no. Freaky Facts books can incorporate elements of both fiction and reality. They might take real facts and embellish them with fictional details to make them more engaging.
One popular 'freaky fiction' book is 'American Psycho' by Bret Easton Ellis. It delves into the mind of a wealthy and deranged young man in 1980s New York. Another is 'House of Leaves' by Mark Z. Danielewski, which has a very unique and somewhat freaky structure and story about a house that is bigger on the inside than it appears on the outside. And 'The Shining' by Stephen King is also a great example. It takes place in an isolated hotel with a lot of spooky and strange happenings.
The unknown elements. For example, in a story where there are strange noises in an old house but you don't know what's causing them. It creates a sense of fear because our minds start imagining all sorts of terrifying things, like ghosts or monsters.
For young adults, 'Miss Peregrine's Home for Peculiar Children' by Ransom Riggs is a great freaky fiction book. It has these really strange and unique characters with special abilities. Another one could be 'The Graveyard Book' by Neil Gaiman. It's set in a graveyard and has some spooky elements but is also suitable for young adults. 'A Monster Calls' by Patrick Ness is also a good choice. It deals with some heavy and a bit freaky themes like death and monsters in a way that young adults can understand.
You could use names like 'Luna Darkwood', 'Morpheus Black', or 'Raven Nightshade'. These names have a spooky and mysterious feel to them, which would be great for a freaky story.
For a really freaky story, names like 'Mortimer' which has an old - fashioned and slightly creepy feel. 'Ophelia' can also work as it is often associated with madness in literature. And 'Vlad' which has associations with vampires and the Dracula legend.
For me, it's the unexplained elements. Like when things move on their own with no logical reason. For example, a book flying off a shelf when there's no wind or anyone nearby.
You might consider 'Caspian Crypt'. 'Caspian' has a somewhat mysterious sound, and 'Crypt' is a very spooky place. 'Persephone Phantom' is also a good name. 'Persephone' is a figure from Greek mythology associated with the underworld, and 'Phantom' makes it even more ghostly. And 'Silas Sinister' is a great choice. 'Silas' is a name that can seem a bit old - fashioned and menacing, and 'Sinister' really emphasizes the freaky nature of the character.
There was a girl who moved into a new apartment. Every night, she heard a scratching noise coming from the wall. At first, she thought it was just mice. But one day, she saw a face peering through a crack in the wall. It was a pale face with sunken eyes. She called the landlord, but when he came, the face disappeared. That night, the scratching got louder and louder until she couldn't bear it anymore. She moved out the next day.