It's a common question that I hear during this time of year. Hang Christmas lights on a metal roof can be a bit tricky, but there are a few methods you can try. One option is to use metal clips that are specifically designed to attach to metal roofs and hold your lights in place. Another option is to use adhesive clips that are designed to stick to the metal surface. You can also use staples, but be sure to use ones that are specifically designed for metal surfaces to avoid causing any damage. Whatever method you choose, just be sure to test it out before hanging all your lights to make sure it's secure.