The only publicized event is
MNSSHP (last year they had a Halloween party at DisneyQuest, but I haven't heard anything about it this year).
Guests at Fort Wilderness are known for decorating their campsite and doing trick-or-treating, but this not a Disney sponsored event. It's been happening for years, so there is no reason to think it won't happen again this year, but as it is not sponsored by Disney, there is no way to know in advance if it is happening and to what extend.
Some of the resorts do have activities that happen (e.g., trick-or-treating), but again, they aren't highly publicized. The Boardwalk used to have activities similar to the ones
PHLtoMCO described at BLT, but I don't know if they're doing it again this year. I hadn't heard of things at BLT before, but being a DVC it might only be for guests of the resort.
I would ask when you check-in if there are any Halloween night activities planned at your resort.