Whatever you think of it as a TV show, “Wahlburgers” is apparently good for the brand. The Hingham-based burger joint operated by the brothers Wahlberg is expanding. When Donnie Wahlberg was in town the other day, he told us that he, Mark, and Paul have as many as 70 sites under contract. . . . Paul was one of the celebrity chefs at a fund-raiser for the Codman Square Health Center, joining native sons John King of CNN (near right) and “All Souls” author Michael Patrick MacDonald (far right), among others.