This past summer we had a leak in one of our upstairs bathrooms. Now the is a mark on the Downstairs ceiling. This week end I decided to clean and paint the mark. Low and behold, as I sanded the area a little my hand busted a hole in the drywall. The drywall was black on the inside and also very thin. I am wondering who I can have check the drywall for mold, the dangerous stuff. I've seen TV shows where the house had mold between the siding and the wall, where they had to remove the whole siding due to the mold. Hopefully this won't be my case. TIA