Led lights are cost-efficient and safe.

       (see photo, shot today). Last season, they did not add anything to the electric bills, and the  authentic ones last for  several years — just make sure they are not exposed to rain, they are turned off after  about ten hours or so, and they’re hoisted high enough to be out of reach of children —

like these ones… but twinkle in slow motion enough to make their faces light up and beam.