mold behind drywall near plumbing 16
https://gatewaywatermoldscope.solsticebrief.com/posts/finding-hidden-mold-behind-drywall-after-a-plumbing-leak-in-st.-louis
You know that faint musty smell near the bathroom wall? It's probably mold growing behind the drywall where a slow plumbing leak has been trapped. The moisture gives mold a perfect dark spot to spread, and over time it can eat through the paper facing of the drywall, making the area soft and crumbling. I had this in my own house, and when I finally cut a small inspection hole, the black growth was way worse than I expected.