The only thing I know of that would cause black spots on the wall is mold. Instead of thinking it's some sign of the Supernatural try pulling out a piece to see if there is black mold behind it. If there is then you'll have to move because it's hazardous to your health.
ANSWER I agree it is likely mold. Most mold is not poisonous and if it is not then all you need to do is remove the molded wall material and try to find the sourch of moisture in the wall that allowed the mold to grow - for more info Google Mold Remediation. Good luck.
It can mean infection, some types of cancers, lack of blood supply, arthritis, or tumors
the cheetahs color are brownish with black spots
That depends on what the black spots are.
dark yellow with black spots
A black Jaguars spots are so hard to see because the spots are also black so they blend into the fur.
A Dalmatian has black spots and white skin
those black spots are black heads caused from to much oil in the ears
its a little conder
Maybe
spots
black spots
Sun spots.