that mold is called stackyvatris (spelling) you will get it anywhere there is constant wetness such as a water leak. Or as you stated a shower or bath. Even if you didnt have air flow in your grow area it would be improbable for that type of mold to grow unless you where constantly feeding it with fresh water. and I mean constantly. as in a constant drip on the floor or down a wall. it is dangerous mold tho, but it takes large amounts of exposer to it.