Mold within furnace part? Is it dangerouse if I have mold in the furnace section, will...

Is it dangerouse if I have mold in the furnace section, will it go with the heavens that blow throughout the house? how can I get rid of it? Is the good filter help out with this problem?
Tin Foil on Grill?
Answers:    Yes,Yes. Call a professional duct cleaning service.The filter will do nothing except verbs the air before its returned to the furnace .You may hold a water leak that getting into your duct work . I'm sure I dont hold to tell you that there are abundant kinds of mold that are bad for you.
You may necessitate new duct work or the insulation might need changed within the ducts.Also make sure your pan underneath your unit is draining properly.