S1·E17 The Big Bank Robbery

When he discovers a bag containing $86,000, Fred's dreams of being a wealthy man finally seem to be coming true. But the money has been stolen from the bank, so Wilma and Betty force Fred and Barney to return the money to the bank, and unwittingly set them up as the primary suspects! The wives set a trap for the real culprits and Fred ends up saving the day.