All that I can remember is a girl, maybe a babysitter, finds a door in an entertainment center that is a secret door to the basement. She finds another girl down there being tortured. The girl already there has a box around her head. The girl that found the door ends up getting tortured by the people who own the house and are in some organization to find what people see when they did. The girl that found the door ends up getting skinned alive so that she can tell them what she sees.

Martyrs (http://en.wikipedia.org/wiki/Martyrs_%28film%29)