mold behind drywall near plumbing 18

https://moldbehinddrywallplumbingnotes.brightsora.com/posts/how-to-spot-mold-behind-drywall-near-plumbing-in-a-rental-home

We noticed a musty smell in the bathroom and when we finally cut into the drywall near the plumbing, there was a patch of black mold about the size of a dinner plate, already spreading behind the wall.