Not halloween but when I was a primary school kid we had a class vacation to the lake district in England. We ended up staying at what was a creepy victoriana style mansion. And being kids we were all convinced it was haunted.

Anyway a classmate of mine was so scared he made himself a cross out of basically twigs.

I of course waited until he was asleep and snapped it pieces also I had joke shop fake blood which I also used.

Woke up to him crying his eyes out and never did ever admit it was me.