It is more in this culture about candy and dressing up as scary stuff. Part of the American culture more than the Catholic church IMO...I never see it promoted in a church.Our "kids" are in their 20s now, but when they were young, our church did have a celebration (indoor carnival) for the kids, but it was loud and obnoxious, and I always came home with a headache, however, they liked it. We passed on the walking around for candy (under my concern it was greedy, I didn't know all the homeowners, and the candy was not good for their health or mine anyway), but I never had a good grasp on how to make it holy. I applaud those parents who are doing so.
I can understand the indoor carnival for the kids there because it is a safer environment that can be controlled.
Things changed in the 70s when nuts put razor blades into candy and poison as well.