Black mold around half bathroom exhaust fan.

We had a new roof put on our home about 6 weeks ago. I am wondering if this could be related in any way. I recently noticed black mold around the exhaust fan. This is a half bath on the main floor and there is a bedroom directly above it. I removed the cover to the exhaust fan and cleaned it all up. I was able to move the motor just enough to feel inside and noticed that it is pretty wet inside the ceiling. There was the attachment to the exhaust and also a coil like tube (like what I have connected to my laundry room dryer. It seemed like the water could be coming from that. I don't know if this is an issue form the new roof somehow or if I need a Plummer, an electrician or someone that works on Air conditioning. Any ideas?