Wuuf is a radio station in Caninewood, the seedy neighborhood in which the video game Grand Theft Scratchy takes place.
Marge and Lisa entered the game, and decided to clean it up. The Wuuf building was destroyed, so Marge placed Maggie inside a duct so she could crawl to a button to change the game's background music. After Maggie accomplished this, the building then played a better song and Caninewood completely transformed.
Behind the laughter
The name of the station is a parody of the radio station WUUF, and is based on the barking sound a dog makes, as the neighborhood is inhabited by dogs.