Girl in the Closet.

Based on real-life events, Girl In the Closet tells the story of 10 year old Cameron, who, after her mother suffered an aneurysm, was adopted by her Aunt Mia, who already had a husband and daughter of her own. Soon after arriving in her new home, Cameron started hearing strange, ghostly voices at night coming from the basement's locked door. Little Cameron would soon discover what was actually behind that door, people chained to the wall, innocent victims of her Aunt's schemes to enrich herself by cashing their benefit checks. It wasn't long before Cameron was demoted down into the basement herself, where she would stay for the next ten years while police thought she was missing.