From the Super Mario Wiki
Ralph Washington is a human character in The Super Mario Bros. Super Show!. He only appears in the live-action episode "George Washington Slept Here", in which Mario and Luigi open a bed and breakfast in the Mario Brothers Plumbing, lie about George Washington sleeping there to attract customers, and proceed to dream about George Washington admonishing them for lying. After all of this occurs, Ralph enters the bed and breakfast and asks them if they have a vacancy. As he is played by the same actor who played George Washington, Ed Metzger, Luigi says that he looks very familiar and asks him for his name. When Ralph says that it is Washington, Mario excitedly asks him if his full name is George Washington (meaning that Mario and Luigi could lie about "George Washington" sleeping there), but he replies with "Ralph Washington. Luigi dejectedly says that the inn is full, and Ralph then leaves.