Ingredients: Goblinoid/Orcish PC, Leadership, Lightbulb (Glass Flask with a Continual Flame in it), spear, ladder.
Firstly, select your base or house, and with the spear, stap a hole into a wooden ceiling.
Secondly, commision your 'lightbulb,' from the local mages guild/etc.
Thirdly, place your ladder under the whole, and climb up it.
Fourth, have all of your goblinoid/orcish followers to use 'aid another'
Fifth, see how many goblins/etc. it took to screw in the lightbulb.
Ta-da!