Within the game's data is an unused conversation between Seymour Skinner and Agnes Skinner. It is about an answering machine message. This is the transcript:
Seymour: "You have reached the Skinner residence. Please leave a concise message at--"
Agnes: "Seymour! What are you doing?"
Seymour: "Recording an outgoing answering machine message."
Agnes: "Without my permission? You're grounded!"
A modified version of Agnes' last line here can be heard in Level 7's ghost playgrounds, but it is hard to hear.
Contributed by psyducklover13