Story about the American plumbers

This story was a story about some American plumbers. Muggle Mr. Mason knew this story and when he and his wife came to 4 Privet Drive to discuss Vernon Dursley's new collection of drills, Petunia Dursley claimed that she had been dying to hear it.

Behind the scenes

 * In the film adaption of Harry Potter and the Chamber of Secrets it was Vernon who told a joke about some plumbers which cannot be considered canon as it seems to be a replacement.
 * It is possible, however unknown, that this story was somewhat like the joke.

Appearances

 * Harry Potter and the Chamber of Secrets