A light fixture is no place to establish a colony. I mean, it has its virtues--it's under the eave protected from the rain, for example. But whatever benefits this location provides are vastly outweighed by being an inconvenience to the humans within the building.
It's a shame because the architects of this young nest were bald-faced hornets Dolichovesula maculata
*, who voraciously hunt other insects to feed to their young--I have read that they even catch their closest relatives, the much hated yellow jackets. Adults feed on liquid sugar, either flower nectar or the juice of discarded fruit. Workers defend the nest bravely and energetically. One memorable time I was attacking a mature nest and the workers kept bouncing off my bee veil, directly in front of my eyes. More often then not these social wasps build their nests high in the leafy canopy of trees, and we don't even know they were there until the autumn reveals the empty nest.
* "Spotted, long little wasp"