I have lived in at least two haunted houses, and I assure you, my mental health is ironclad. I guess it all depends on what your spiritual philosophies are.
One, is my parent’s home in an historical neighborhood and our house was built by the man who helped invent the television. Lights turn off and on intermittently, the lights blink when we talk about him, and sometimes it looks like you can see him standing in the upstairs window when you come around the corner. He appears to be friendly, though and we’ve lived peacefully with him for years. Of course we’ve considered that it’s the wiring, etc. but there are too many coincidences.
In the second, I was living by myself and just never felt like I was alone. I’d see strange shadows, things would move when I wasn’t home and then there was the bed shaking. Many times, wherever I was sleeping (couch, bed) the bed would start shaking as if someone had grabbed it from the bottom and was shaking it vigorously. I tried to explain this away for years(fault line, small earthquakes, seizures, trains, wind) but it was too intense and consistent to be explained. I mentioned it only to a few friends until multiple guests staying at my house noticed it too.