The Addams Family Tree - S1-E5
Continuity mistake: When the mailman opens the mailbox to drop in Adam's mail, Thing snatches them and then closes the box. When Wednesday goes to the inside box, Thing hands her only a single letter.

Starring: John Astin, Carolyn Jones, Jackie Coogan, Ted Cassidy
The Addams Family Tree - S1-E5
Continuity mistake: When the mailman opens the mailbox to drop in Adam's mail, Thing snatches them and then closes the box. When Wednesday goes to the inside box, Thing hands her only a single letter.
Morticia: Think of Romeo and Juliet.
Gomez: They died.
Morticia: Oh, but what fun they had those last three days.
Trivia: Although it was kept a secret for years, the part of Thing was performed by Ted Cassidy. He sometimes had to travel to the studio to do it, even if Lurch wasn't in the episode. Though in a few episodes, where both Lurch and Thing appeared in the same shot, assistant director Jack Voglin performed the part of Thing.
Question: How was effect of the light bulb that lit up whenever Fester put it in his mouth achieved?
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