When I was a kid in Iran, around 1999, I remember there was a TV series where a girl and her family had bought a hotel and were living there. The girl had a fringe haircut and had become friends with a ghost that only she could see. The series was real people, but the ghost was animated, of indeterminate gender, and looked a bit like Casper.
Regarding plot, I remember going down the stairs, lots of stairs, and that the building was quite old as well.