I never have, but man, my husband and his brother have some great stories. Pretty early–say, late middle school–my husband decided it was more fun to stay home with his dad and set up elaborate scares for the neighborhood kids than to go trick or treating himself.
One year, my FIL put a big amp out in the yard under a table with a cloth over it. In the middle of the table, they put a HUGE bowl of candy. He and my husband hid in the living room with a mic and watched out the windows for kids. The kids, of course, would come up and look around, see the porch light on, and be confused. (You gotta be kidding me! We can’t be this lucky!) Some of the more suspicious ones would peek around looking for a person, but wouldn’t find anyone. Then, finally, they’d sneak up to get a handful of candy, and they’d scare the pants off of them! The kids would laugh and think it was fake after they got over the initial “boo!” scare–but then my husband would start making comments on their costumes and they’d get freaked out.
After my husband went to college, his brother took up the cause with their dad. One year, my FIL sat on the steps handing out candy, and my BIL had dressed up in a really elaborate costume that showed only his face–and that was covered in makeup. He looked like a Victorian era wax sculpture–only incredibly lifelike. He can also stand eerily still. Even adults who brought kids up were fooled and asked my FIL if they could “touch it.” Of course, he’d say sure, go ahead! My BIL says he had the time of his life waiting for exactly the right moment and way to startle each person. If someone leaned in really close, he’d just turn his eyes toward them and flinch a little, and they’d jump back. He got a group of teenage girls really well by jumping off the steps suddenly–one shrieked and ran about 10 feet before stopping and turning around.