Ok first you need to get a party of 2, you and someone else, get a costume each (don't know if it really matters if its the same or has to be diff), go to one of the Bomb Laterns and thats all I did. :D
Nice, But can someone please tell me how this Trick or Treat works? I have ran all over Sandy talking to the NPC's and can't find the event moogle either. Where do I get the treats to give them?