Edwards has vanished from the public stage and even from the lives of most of his acquaintances since the scandal. He’s spotted occasionally in the supermarket in Raleigh, N.C., and put in an uncomfortable, largely silent appearance at an aide’s recent wedding, friends recalled. But he appears largely to be seeking a more private redemption with low-profile charity work in El Salvador, which he’s visited three times, and now in Haiti, where an associate said he was on Thursday.