clorox and water... mix a cup or two of clorox in about a gal of water... use a clean cloth or sponge, squeeze well enough it doesn't drip and wipe wall. let air dry... wipe several times if required. be careful and don't drip on carpet/upholstery.
mom had a wall in her house that was constantly shaded and her plaster walls constantly tried to mold/mildew... this was the solution we used to battle the evil fungus.
2015 FR Georgetown 378TS