I believe this came on as a Saturday morning movie, like the ABC Weekend Specials in the early 80’s.
It begins in the early 1900’s with a young girl running from bad guys in a tunnel. She falls and hurts herself and ends up dying. Decades later, the house that is above the tunnel is believed to be haunted. Two kids end up finding the tunnel behind the fireplace, find the girl’s skeleton and the locket she was wearing, and the girl’s death is finally explained.
This is not The Haunted Mystery Mansion or Child of Glass.