What is the Dewey, Cheatem and Howe joke?

“Dewey, Cheatem & Howe” is a classic play on words that humorously and fictitiously names a law firm. The joke is in the phonetic pronunciation of the names:
Dewey: Sounds like “Do we…”
Cheatem: Sounds like “Cheat ’em…”
Howe: Sounds like “How…”
When said together quickly, it sounds like “Do we cheat ’em? How?” implying unscrupulous or dishonest behavior, which is ironic and humorous given that it’s supposed to represent a law firm, an institution expected to uphold justice and integrity. The joke plays on the stereotype of lawyers being deceitful or tricky. This fictitious law firm name has been referenced in various media and comedy sketches over the years.
It has been used in various media and comedy contexts over the years. One of the most notable examples is from the radio show “Car Talk.”
Car Talk: This was a popular American radio talk show broadcast on National Public Radio (NPR) for over three decades. The show was hosted by brothers Tom and Ray Magliozzi, who discussed cars, car repair, and shared humorous anecdotes. They often made reference to their fictional law firm, “Dewey, Cheatem & Howe,” as a running gag. In fact, in Harvard Square (Cambridge, Massachusetts), where their office was located, there was a window sign for “Dewey, Cheatem & Howe” as a nod to this joke.
The name has also been used or referenced in various other TV shows, movies, and books, often as a humorous nod to the stereotype of lawyers being less than scrupulous.