It is a place in Sicily. The family for whom the place is named was originally Cara, which means dear, beloved. Vaggio is probably a Sicilian dialectical form of viaggio, journey. In contemporary Italian, everyone says "Buon viaggio!" when departing; the English equivalent is "Have a nice trip!" If I were going to Sicily, I would certainly have every expectation of a nice trip, even if I risked dealing with characters like the painter, Michelangelo Merisi da Caravaggio.