Mold problem in apartment walls?

If you have mold covering the inside of your drywall, it is unhealthy and dangerous to be living with it constantly. There is no easy solution - the drywall will need to be removed, steps taken to make sure there are no leaks in outside walls, which would allow mold to form on newly replaced drywall. You would probably need to move out of the apartment temporarily while the work is being done.