Scacciadiavoli

I'm not 100% sure of the title - it means 'drives out devils' - and it is (supposedly) placed over doorways etc to keep bad luck, devils, hobgoblins, Derek Acorah (q.v.) etc out of a house. But I don't know if it should be 'scacciadiavolo'. If one is called a scacciadiavoli, how do you say two of them? Perhaps it's invariable.
Anyway, Jude suggested I reveal my secrets on how to find a place in Venice. This is the easiest type. You know the number - 2483. So go to ombra.net [which is the same as venicexplorer.net but quicker to type] and click on 'Venice Civic Number' - about halfway down the list on the left. A screen will appear with four boxes. In the top one you select the sestiere. You don't know which one it is, but there are only six to try. In this case, the number is higher than the highest number in Santa Croce, so that leaves five. But they are in alphabetical order (Venice first, then Giudecca etc), so Cannaregio comes first. Ignore the next two boxes and put the number in the last box. Click 'submit'. You will get the calle (or fondamenta etc) where this number is. You may get more than one answer if there is 2483A, 2483B etc in a sestiere. At least they will be adjacent to each other. Click on the result, and a map will appear with a blinking red dot at the address you clicked on. Make a note of where it is. Then go to veniceconnected (maps.veniceconnected.it) and put your pointer on the map as near as you can to where the red dot was on ombra. Have a look around till you find the number. Bingo! [ombra.net is not always correct, as in this case, but it only makes life more interesting, don't you think?]