Famed French actor and singer Fernandel headlines this comedy centered on a case of mistaken identity involving a hapless vacuum salesman. Door-to-door vacuum salesman Casimir has a strange knack for getting himself into complicated situations. One day, after knocking on the door of local artist Paul-André, Casimir finds himself in his biggest jam to date. After exchanging a series of romantic letters with wealthy South American Angelita, Paul-André has agreed to tie the knot. But now that Angelita is actually coming to town, Paul-André has gotten a paralyzing case of cold feet. By the time Angelita arrives in town Paul-André is already long gone, leaving the love-struck hotel owner to surmise that Casimir is the man who won her heart through correspondence. At first Casamir isn't quite sure how to get out of the predicament, but upon discovering that Angelita owns 1000 hotel rooms he surmises that could mean she needs just as many vacuum cleaners, and continues the ruse in order to make the big sale.