Maybe you remember this one from school. It was filmed by Encyclopedia Brittanica's Short Story Showcase.
As an educational film, it's short on production values, and its big-name star would grow up to be Ed Begley, Jr. Cinematically, it's a really terrible movie.
Even so, the story was powerful. I remember it to this day. I haven't yet read the short story by Shirley Jackson, but I will, and soon.
If you haven't seen it, or your kid hasn't seen it, it's available on YouTube, and worth the 20 minute investment.