It is a claymation movie I used to have on vhs as a kid. It was not very long so it could have been a short TV movie.
A brother and a sister are at a fair or something. One of them wants to go on a Halloween themed ride similar to the “it’s a small world after all” ride at Disney world. The ride stops and gets stuck in the dark. The children get out of the ride car and look for a way out. On the way they find monsters inside that are alive. Such monsters include witches, mummies, and skeletons. Ultimately they find their way out at the movie’s close.