“Wrecked” turns strangers fighting for survival somewhere in the Pacific into a laughing matter. The single-camera, half-hour sitcom begins with a daring, and ultimately failed, rescue attempt after a commercial flight crash-lands on an uninhabited island. Now unplugged from the rest of the world, a diverse group of survivors struggles to navigate their makeshift society while also learning to live without such modern comforts as indoor plumbing, cellphones, social media, and fast-food restaurants at every corner.