[HayZee518]

anything you put on top of what's already loose will itself loosen up with time. if your wall is sheetrock then make a sheetrock repair. if the base wall is metal or wooden tath then use plaster of paris or spackle compound with horsehair or fiber filler. plaster or spackle needs to be "keyed" into the lath just don't slop it on - make it the consistency of lumpy peanut butter and force it into the lath with a trowel.