Ultrafast disordering observed after photo-excitation challenges the conventional picture of photo- induced transitions where symmetry-breaking takes place along a single collective coordinate. We propose that key spectroscopic signatures of these transient disordered states can be revealed through stochastic resonance, a hallmark of nonlinear stochastic dynamics. Studying the disordered phase of Holstein model we show that, at given frequency, the linear response as a function of temperature has a peak, which indicates enhanced coherent switching between metastable configurations. From this resonance, we extract the intrinsic stochastic transition timescale and energy barrier separating equivalent local minima. This mechanism offers a new perspective to identify and characterize hidden disordered phases in driven many-body systems.