Although there is no actual state law regarding hospitals they are, without exception, posted and that is one of those cases where the prohibition will be STRICTLY and IMMEDIATELY enforced under the guise of "trespassing".
Same in Ohio. No state law, but they are as far as I know always posted. However, state law does prohibit CCW in, "Institutions for the care of mentally ill persons". Some medical hospitals have at least one floor dedicated to mental diseases. This could get confusing / sticky even if the hospital isn't posted.