The lightbulb never gets changed. It's still there buried under layers and layers of improvements meant to work around the limitations of the dead lighbulb including several other partially finished lightbulbs and an array of mirrors to try and cast some light around the room. The last time someone tried to go in and actually remove the lightbulb, they were lost and never returned. Legends say they're still there trying to wrestle the bulb out from underneath everything.