I don't know why all these people seem ok with a tenant MODIFYING THE ELECTRICAL SYSTEM of a unit. If I have a indoor tomato plant that I want to grow indoors, I don't change the electrical so I can have 24x7 grow lights! Ignoring the legal issues right now, just thinking about someone growing enough plants that they have to put out tarps, fans, lots of lights, run scaffolding or something from the ceiling to support all these plants, is ridiculous. I've seen plenty of home remodel shows (holmes on homes has an episode) where the owner came by to discover an illegal grow operation and the humidity/mold/electrical completely destroyed their unit. No way in hell would I rent to them, no matter how much extra they were paying.
I am pretty sure you can grow MJ without all that crap, its a plant that grows in the wild so if this was really about just a little for personal use they wouldn't need that junk. DO NOT RENT TO THEM.