Make sure that the wall and the dresser drawers have some acutal thickness. Shadow maps work a lot better when there's some real substance to an object, just a single polygon layer or coplanar double-sided polygons can cause such artifacts. In the case shown, the wall could also be fixed by unchecking its "cast shadows" flag. If everything else fails, you can still crank up the "min shadow bias" on that shadow casting light or switch it to using ray traced shadows.