Oh, I am SO late posting this . . . Travel Goddesses, please forgive me.
The Corte Campana, recommended by Rick and run by Ric (!), a native Venetian, and his wife Grace, a native Californian, is terrific. It's in a centuries-old building, part of which has been owned by Ric's family for generations; it has only three bedrooms, in which Ric and his sibling(s?) and parents slept when it was "merely" the family home;it's charming; it's a short walk from St Mark's; it's quite reasonably priced; and Ric and Grace are very friendly, helpful, and knowledgeable. Go!