80s/90s movie I don't really remember well but I think some kid was trapped in a house with ghosts (but they were not really the hostile type) and the main ghost was a pretty little girl. I think she had died in a fire?
There was also some old lady who turned out to be the girl's jealous sister or something like that and she might have been the killer, not sure?
I'm sorry but seriously I can't remember anything else.
Please help!

Lady in White?

Actually, try the Tower of Terror movie (1997) - my son watched it a while back on TV - the little girl was a singer/dancer type, there were other ghosts in the hotel - all period type, there was something to do with an elevator... here's a snippet of the plot you described from wikipedia:

It is then revealed that Abigail was the one responsible for the disappearance of the hotel guests on the elevator, including her younger sister Sally, born Sally Gregory,[2] out of personal vendetta and jealousy against her sister's booming career. Buzzy then realizes that what they did actually gave Abigail the means to complete her spell. The team then rushes back to the hotel, but they are too late

That's it! I just watched some related videos on YouTube and remembered most of the movie.
Thanks so much :)

:)