Not long after moving into their dream home, Tom and Sarah discovered it came with an unwanted – and unwelcome – guest.

No, I’m not talking about a poltergeist, but something much more insidious and, if unaddressed, destructive.

Sarah discovered it one day when she reached for a platter that she used only for the holidays. The small patch of fuzzy, greenish-black growth was creeping along the far back wall of the cabinet, and it looked like it had made itself at home.