I watched this movie on TV when I was a kid in the 80’s. Set present day (80’s). The people in the movie were trying to solve a mystery of a girl that died and was never found. There was a cameo necklace and her remains were finally found under the floorboards in an old house. There was a note that led them to find her there. Please help me find the name of the movie.
How about “Mystery Mansion” (1983)
http://www.allmovie.com/movie/mystery-mansion-v34204