When I was in grade school, so very long ago, one of my teachers showed our class a reel-to-reel film of one of Ray's short stories. I remember that it was really creepy, but I can't remember the name. It involved this guy who was receiving menacing phone calls; when he would answer, a strange, evil-sounding voice would basically repeat everything that he said into the phone. These phone calls persisted, and drove the guiy mad -- to the point where he climbed up a telephone pole and opened the transformer. The film ended with a blinding white light shining out of the box.
Does anyone know what this story is?

See the topic "looking for Dial Double Zero" under "Favorite Book/Story."