Assuming this is a serious question and referring also to your earlier thread on this, if I wanted to locate someone then the first choice would be to go to a location where someone is likely to know of them, past or present. Failing that (in the scenario you indicate) I would try to find a way to telephone the local chamber of commerce, a nearby establishment (shop, restaurant, hotel) and see what can be gleaned. One could even contact the local press and/or the police for advice - in the case of Sicily, the church might be a useful avenue, even by starting with contacts at a catholic church near you. Sadly, I think it unlikely any embassy or consulate (yours or theirs) will prove of the slightest help, but you could always think of them as a very last resort - if you are completely desperate.