Is black mold behind wall urgent for AC system?« Back to Previous Page

We've lived here for 2 years and just noticed a patch of black mold in the corner of our master bedroom closet, behind some storage boxes. It's on the wall that faces the outside of the building. With the humidity lately, I'm worried it's spreading quickly behind the wall. How urgent is it to get a professional to deal with this, and could it be affecting our AC system?