My 1948 house has an illuminated house number that is wired in on the doorbell circuit. Since there's no switch, the bulbs stay on all the time. It takes screw in type E-10 base lamps, but nowadays the bulbs are only rated to last about 30 hours. I want to install a photocell so that it only lights up at night. Anyone ever done this?

Better yet, if anyone knows how to convert it to LED with the photocell?