Universal scaling features of polarization switching are established experimentally in rather different classes of disordered ferroelectrics: in well-studied lead-zirconate titanate (PZT) ferroelectrics, in recently synthesized Cu-stabilized 0.94(Bi1/2Na1/2)TiO30.06BaTiO3 (BNT-BT) relaxor ferroelectrics, and in classical organic ferroelectrics P(VDF-TrFE). These scaling properties are explained by an extended concept of an inhomogeneous field mechanism (IFM) of polarization dynamics in ferroelectrics. Accordingly, disordered ferroelectrics exhibit a wide spectrum of characteristic switching times due to a statistical distribution of values of the local electric field. How this distribution can be extracted from polarization measurements is demonstrated. Generally, it is shown that the polarization response is primarily controlled by the statistical characteristics of disorder rather than by a temporal law of the local polarization switching.