Help with an episode

I need help finding an episode, I think it may have been this show. I'm looking for a horror movie or possible TV show similar to night galley or new Alfred Hitchcock presents about a woman in an apartment that has an amputated leg trying to get her. At one point the leg gets her knocked out and begins dragging an electric carving knife towards her. At the end you see her acting strange talking to a friend, and the camera pans to under her dress to reveal the leg has now been seen not her with her real leg presumably amputated and replaced with the evil leg, at also hints that she too is also now possessed.