I remember the story of a blind man that worked all hours in his carpentry shop; the neighbors were very worried because he would work at night with no lights on. He finally relented, turned the lights on and the neighbors felt better.
Actually, that's not unreasonable. Burglars are more likely to break into a business building that is unlit at night, on the theory that it's almost certainly unoccupied. And even if they have reason to believe it's occupied, the cover of darkness improves the prospects for successfully robbing the occupant. This is certainly no more irrational than people putting their home lights on timers when they're out of town.