The celebration of Halloween is pretty recent here in Italy and the commercial aspect is preponderant as this tradition really has no ties with the Catholic tradition except for its proximity to All Souls Day on November 2nd and the name (Halloween comes from All Hollows Eve - the evening before Hallowmas, all hallows mass, better known as All Saints Day. The name however possible also derives from the pre-Christian-era saying all allows even - the eve when all is permitted). Originally, after its establishment in 610 A.D., All Saints was celebrated in May but it was then moved to November 1 in 1048 A.D. to try to overshadow the pagan Celtic celebration of Samhain, the end of summer. During this celebration, people left food out for the dead and it was believed that fairies and elfs played tricks on humans, which is where the trick-or-treat tradition comes from.
As a child, growing up in Italy, Halloween was our private celebration. My mother used to bring over decoration from NY and we we got dressed up and were allowed to invite our best friends for dinner. I remember Venetian children of the end Seventies being quite puzzled as to why they had to come to dinner wearing a costume, when clearly Carnival is in February, but kids will be kids and any opportunity to get dressed up and tell ghost stories is a good one. I also remember my nanny taking a boat and a bus out of Venice on a quest to find a pumpkin only to come back after half a day with a yellow, warty pumpkin no larger than a tennis ball that a distant cousin of hers had grown in his garden. These days, I no longer have that problem. Supermarkets are full of plastic gadgets and fresh orange pumpkins and some even sell pumpkin or ghost shaped cookies but the more traditional aspect hasn't really caught on, creating a bizzare jumble of practices. Clubs and bars have Halloween-themed parties making it more of a fun evening for students than children.