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.
I'm going to suggest that it was Polterguests, which was a British comedy series that ran for one eight-episode season. In that series, there was the mother, Annie, a former ballet dancer, and her ten-year-old daughter Ella. Unfortunately, the daughter didn't have a fringe haircut; there was a boy who appeared in one episode who had a fringe haircut. The girl often went down a set of stairs into the basement where she had first met the ghosts. There were three ghosts (named Tristan, Kneecaps, and Squiffy), who helped with the running of the hotel, but it went badly. Unfortunately, the ghosts aren't animated either, they are chroma-keyed into many of their scenes. But this is the closest series I could find to what you described.
