Mold needs standing moisture, and Anaheim's older housing gives it plenty of chances to find some. If you own one of the Craftsman bungalows in the Colony Historic District, or a mid-century tract home in west or central Anaheim, you likely have a crawl space under the floor and an attic above the ceiling. Neither one gets checked until something starts to smell off. Add galvanized plumbing that's decades past its intended life, and a slow leak inside a wall or under original hardwood becomes the top cause we run into.
Winter rain does the rest. Between December and March, water works its way through worn roofing, hairline cracks in old stucco, and flashing that's been baking in the sun for fifty years. It gets in, the surface dries, and the cavity behind it stays wet for weeks without anyone noticing. In Anaheim Hills, we see a different pattern just as often: an upstairs bathroom leak in a two-story home that quietly turns into a ceiling stain, then mold, in the room below.
A dark, splotchy patch on drywall or framing, paired with a musty smell that's stronger when the AC kicks on, is worth acting on. So is a cough or sinus headache that eases up the moment someone steps outside — that's the air inside doing the damage, not a coincidence. Leave it for the inspection. Scrubbing or scraping it yourself just launches a fresh load of spores into the room you're standing in.