Most mold is unmistakable, but sometimes small or largely hidden growths just make a surface look dirty. A quick test for mold can be done when you dip a swab in diluted bleach (1 part bleach, 16 parts water) and dab it on the wall. If the spot quickly lightens (or keeps coming back after cleaning), assume it's mold. Mold test kits are available that detect the presence and identify the type of mold, but they won't help determine the cause or what to do about it.ncG1vNJzZmivp6x7p63MoqOyoJGjsbq5wKdlnKedZLmqv9Non6ivXam8bsDErKtmnp%2Bneq67y51m