Need help with the name of a movie.?

Hi, I've been trying to remember the name of a really old movie that I watched when I was younger. It was probably meant to be "scary" but, like I said, it was old. All I remember about it was that it was set in a really strange town (I want to say western) and there was a family who going on vacation there. The town was deserted, I think. Towards the end, the parents of the family became possessed by the "curse" that the town supposedly upheld and the kids ended up getting away. I do remember a scene where someone took a knife, cut into a chair and green slime spilled out. It was a really weird movie. I've been trying to think of the name but it was years ago since I last saw it.