Trivia: In this episode, as Gomez begs Fester to kill him, Fester says "You're my favorite nephew." In the first Addams Family movie (1991), we hear that Fester and Gomez are brothers.
The Addams Family Goes to School - S1-E1
Trivia: This is the only episode where the real house used for the exterior is seen. Also, the wrought iron fence is seen to not go all the way around the property.
The Addams Family Tree - S1-E5
Trivia: In the quick cut scene, Thing comes out and grabs the mail from the letter carrier. This is a re-use of the scene from the pilot episode "The Addams Family Goes to School."
Answer: Basically from what I understand, they stuck the innards of a small flashlight into the base of the bulb and put a little switch on it. When he put it in his mouth and bit down, his teeth would hit the switch, which would turn on the flashlight and made the bulb light up.
TedStixon