Try Goof-Off or Methyl Ethyl Keytone (MEK) both which dissolve water based paint (latex wall paints) and evaporate very quickly, however when it dries if it's on the screen again then it will dry there. So you need to wipe off with clean areas of a cloth quickly to transfer the paint to the cloth and not back onto the screen.
Since both are extremely powerful solvents, it's highly advised to test using a cotton swab on a lower corner someplace small and allow to dry, hold at a angle to see if it will damage the screen.
If it's small tiny flecks like spots, you may use a plastic credit card or plastic paint scraper and lightly pass over the screen and chip them off.
Oil based paints are a different matter, I'm assuming here the walls were painted to get that sort of splatter on the screen.