Hello,
after a little research in the lists of the all local italian state archives (Archivio di Stato), you can try to find the application for passport of your ancestor or the real passport. There are records about issueing italian passport from 1600's to 1900's
Only if your ancestor was born in one of the provinces below:
Cagliari-Firenze-Livorno-Milano-Modena-Napoli-Palermo-Parma-Pescara-Pistoia-Ravenna-Roma-Rovigo-Savona-Siena-Teramo-Torino-Trapani-Trento-Treviso-Udine-Venezia-Vercelli
I hope it helps
bye Riccardo