I think it was the Maniac's Hideout, since he said he had been serial killing in the area for years. The house was haunted because of how many people he killed in there (the locked room).
Thanks! I wanted to leave it open to interpretation. It could just be a random haunted house in the woods...OR it could also be the previous home of Lucy's father (the ghost kinda looks like her father). It's also an excuse to get the weapon and the lamp
