Is there a word for a person who's obsessed with lights?

Well I don't know if there is a word in common use, but the common suffix for a 'lover of' is 'phile'. Some words have been brought into common use that may not have even existed previously. Ie. Japanophile - someone who has a love for all things Japanese.

Therefore using the Latin for light (Lux) you could maybe create a word like Luxophile or Lumophile, or even Photophile if photomania is a craving for light

Personally, I just use photophile. People (especially those who are 'obsessed with lights') usually understand where I'm coming from. I describe a photophile as someone who is 'obsessed with' watts, lumens, efficacy, footcandles, the sun, bulbs, L.E.D.'s (different colors of L.E.D.'s), flashlights/headlamps, lanterns, light displays, refraction (see: prism) just to name a few genres. Someone may only identify with one, some, or all, but may still be a photophile.