The ending

It's ambiguous.

Straight story - It looks as if the ghost and her demon went to hell. Why? Because it seems as if her family did not run away, she killed them then committed suicide.

Inner Story - This is a story about reintegration of multiple personalities. The real patient is the haunted house. Inside her mind is a personality from a kind of quasi-Victorian age. She shares the "house" with another personality...the demon side. At the end they are both destroyed as they become reunited with the main person.

What I thought it meant was that she (and her inside demon) go to hell. I think that because she didn't see the light. The room starting getting really dark, instead.

I may change my mind after reading others' opinions. But that's what I thought, when I saw it.