Is it ensure, insure, or assure?
"fall guy, victim of a deception," 1903, of uncertain origin, possibly an alteration of Italian pazzo "madman" (see patch (n.2)), or south Italian dialectal paccio "fool." Another theory traces it to Patsy Bolivar, character created by Billy B. Van in an 1890s vaudeville skit who was blamed whenever anything went wrong.
"Poor Rogers," Vincent said, still smiling, "he is always the 'Patsy Bolivar' of the school."
"Yes," Frank answered, "if there are any mistakes to be made or trouble to fall into, Rogers seems to be always the victim." ["Anthony Yorke," "A College Boy," 1899]
[1903+; apparently fr the name of Patsy Bolivar, a character in a minstrel skit of the 1880s, who was blamed for whatever went wrong]