Ok I think I determined WHY I have mold. What's happening is the walls are getting wet due to the increase of humidity from lack of ventilation. There's low ventilation because I light proofed the closet so well. I have no idea how to install an exhaust fan. I don't really want to get in the attic to run the electric, so I don't know what else to do. So far, I've been opening my closet for 15 min or so a couple times a day. I put another very small fan in the closet as well to help with circulation. I put a "shield" up to direct the light to the plants to cut down on light loss when door is open.

Any other suggestions? Does anyone know an alternative to installing a hardwired exhaust fan??