Whats the movie called where the kids are buried alive?

I saw it on TV when I was a kid and was wondering if anyone knew of the movie and knew the title? There was a family who moved into a house It was haunted with the ghosts of the kids who had died being thrown into a cavern underground and being buried hence stuck in the cavern. the radio frequencies picked up voices and showed visions to i beleive the father. The father i beleive also found pictures of the murders planning under the murderers bed when he found pictures drawn of kids living underground after being buried. ringing any bells?