I probably saw this movie in the late 80s or early 90s. It may have been a children's movie, but since neither my parents nor school had the best track record in picking appropriate movies, it may have been an adults' movie with a PG rating. I just remember that it terrified me.
It was a live action colour movie about a family moving into what turns out to be a haunted house. Two scenes I remember vividly. First is a large bloodstain which the new owners order a maid to clean up. It's easily removed, causing scoffing from the new owners, but it soon reappears. Second is the bit that scared me. One of the new family, probably the mother, is sitting at a dressing table and looking in a mirror. Suddenly her reflection changes to show her looking hideously old and decayed, but a few moments later it changed back.
It's possible this is an adaptation of The Canterville Ghost, but the only version of that I've seen since then was animated.