Why are we geezers required to act our age? Don’t even try at this year’s Halloween event on Treasure Island Oct.30. It’s the annual Ghost Ship party and if you wear a really great mask who will ever guess how old you are? Bring earplugs because the dj’s will be detonating techno punk. But it’s as much an art event as a dance. The place is chock full of mutant cars and other unworldly and often sophisticated installations, the highlight of which is an enormous ghost ship. Tickets sell out early.