Happily getting an early start on the Halloween festivities, Selena Gomez paid a visit to Knott’s Berry Farm’s Halloween Haunt in Buena Park on Saturday night (October 24). The Disney darling was already fully into the Halloween spirit, smiling as she posed with some costume clad monsters at the annual event. Meanwhile, Miss Gomez happens to be the spokesperson for this year’s Trick-or-Treat for UNICEF, of which she tweeted last night, “7 days til Halloween…….Be sure to tune into the UNICEF live chat on October 29th at 4pm PST.”Of the money-raising efforts, Selena previously told press: “Trick-or-Treat for UNICEF invites children and adults alike to make Halloween count by joining UNICEF to do whatever it takes to help save children’s lives.”