I've got a job that consist of converting a classroom into 2 separate bathrooms. The lights that are in the existing classrooms have separate switched ballast. They were using 12/3 to feed through the fixtures to supply each ballast. Since they are converting them to bathrooms, I will need to install a bath fan in each bathroom. The owner wants to tie both ballast on 1 switch, which will leave one unused wire. Can I use the unused wire for my bath fan switch? Seems to me like there's something in the code that says you can't use the light as a raceway. I don't have my code book handy. Wonder if anyone can help me out? Thanks a lot for your input.. Steve

410.31 says that to use a fixture as a raceway, it must be listed for such use.
Don

If these fixtures are the type that can be connected end to end, then thhey most likely are rated as a raceway, but check first. Can't you attach a j box to the fixture to avoid any violation?