A couple other Halloween experiences I've had playing, besides the Bloody Barber who was making human parts into creepy scarecrows and jack o lanterns...
1) Using Dread, we played as kids who were invited to a rich kid's halloween party. The kid's dad owned the steel mill and we were all kids of his workers, so it was a 'give back to my workers' thing. The parents all went out so we started playing sleepover games... like one with a voodoo doll you'd play hide and seek with. He'd chase you with a knitting needle and stab at you. You had to keep salt water in your mouth because if you opened your mouth - say, when it stabbed you - it could possess you. During the curse too, we didn't know it at the time but our costumes became 'real' so the kid who came as GI Joe was actually relatively safe. The poor kid who came as the 'robot' - the washing machine box wrapped in tin foil - not so much.
2) My friend was going to run a horror D&D, using some Ravenloft stuff, but decidedly NOT Ravenloft. He started with the Hell House(?) adventure. The setup was we were orphans, and the bullies said we were chickens. So we decided to stay at the Wycker House overnight - no one ever had. All kinds of bad things happened to us ten year olds. We survived, and saved the two NPC brother and sister, who became paralyzed after she hid in the dumbwaiter and it dropped.
Fast forward ten years, we come back together to the brother's funeral. He'd never been able to cope with the experience and swore he'd destroy the House. He, and we, found out the house would reform when destroyed. He did discover the basement had a portal to The Other Side, and his theory was if it was destroyed from the mirror side, that would solve everything, but ... the House arranged his death first. So, we were put on the path to avenge our friend.