can you use indoor extension cords outside for christmas lights

No, it is not safe to use indoor extension cords for outdoor Christmas lights. Outdoor extension cords are specifically designed to withstand the harsh outdoor conditions and have the proper insulation to protect the wires from damage due to moisture or other elements. Using an indoor extension cord for outdoor lights could potentially cause a fire or electrical shock. It is always best to use outdoor extension cords and make sure they are rated for outdoor use and carry the proper certifications.