There are a few ways through which you can hang your Christmas lights without nails. One way is to buy heavy-duty tape which you can use to stick the lights to the wall. Another way is to use hooks which you can fix using sticky tape. You can hang your Christmas lights by using hooks alone. Just drill a hole into the wall, insert the hook into it and push the hook outwards. The hook will hold the Christmas light at the top.   It is important to know beforehand the kinds of lights you are dealing with before you hang them. If they are the traditional cylindrical ones, this is easy. However, if you are hanging star or icicle lights, then you will need to purchase or build a hanger that can hold the lights outward at a good angle.