I saw this scene on US cable television around 2005 or earlier. An old woman was threatening children who may have broken into her junk-filled house by pushing them towards them a round hole in the wall filled with saw blades rotating around the center, like the mouth of a sandworm. It was in color, and I don’t remember if the kids were actually killed.
Sounds like a scene from “Matilda” when the principal threatens kids with “the chokey”.
That wasn’t it, I’m afraid. The chokey is a small closet without the circular hole-in-the-wall motif, and Matilda is an innocent-looking movie.
I have an impression of an even older, crueller woman, and a close-up view of the horrible device turned on and spinning.