What film/show ends with a girl finding skeletons of a missing family hidden behind a fireplace?

I have a half-memory of a seeing a film when I was a kid, but as many times as I've searched for it using various search terms I've always come up blank. That being the case, does anybody recall seeing a film like I'm describing? It's been bothering me for years...

What I remember is that one of the characters (likely the lead) was either a child or teenage girl. She had recently moved to or was visiting an old house of some sort and hears a story of a family that lived there a long time ago; possibly during the Civil War. Nobody knew what happened to the family apart from that they had simply vanished. Toward the end of the film the girl discovers some sort of clue to the disappearance in a lamp or lantern in a shed or an old barn. This leads her to check out a fireplace in the house where she finds a secret hiding place or escape route and the skeletons of the family. It turned out that they had been trying to flee from someone who had followed them into this tunnel and killed them and sealed it up behind them.

That's all I can remember. I know it's not a lot to go on, but if anybody knows what it is could you please tell me? :oD