I was thinking something more how to say it? Tense? Instead of some big monster or zombie, maybe a haunted hospital by someone who died there… And you can go into the morgue and still see the body covered, a hand peeking out.
If we learn how I will add some interactables and maybe can look into spooky events like somethign noisily falling when you turn from a perfectly fine untouched room… Or I can go for the stuck in time haunted approach