Halloween Trick-or-Treat Event On Friday October 26th, 2012, OneWorld Community Health Centers will host the annual Trick-or-Treat Halloween event for kid’s ages 0-12. Families are welcome to trick or treat throughout the halls of the Livestock Exchange Building (4920 South 30th Street) from 4:30p.m. to 7:00p.m. The event is free and open to the public.