Have the same problem in several bathrooms in my sims houses - no ceiling light, no MOO used - only things even in the bathroom are toilet, sink and tub/shower. Even tried replacing the door with an arch and removing the door - problem continues. Have had to cheat teleport my sims out of the bathroom. Oddly enough - sometimes there is no problem (they can use the bathroom just fine) and then suddenly there is (they can't get out). Routing in generally has been getting much worse lately.