  We study the situation where two point like mirrors are placed in the vacuum
state of a scalar field in a two-dimensional spacetime. Describing the
scattering upon the mirrors by transmittivity and reflectivity functions
obeying unitarity, causality and high frequency transparency conditions, we
compute the fluctuations of the Casimir forces exerted upon the two motionless
mirrors. We use the linear response theory to derive the motional forces
exerted upon one mirror when it moves or when the other one moves. We show that
these forces may be resonantly enhanced at the frequencies corresponding to the
cavity modes. We interpret them as the mechanical consequence of generation of
squeezed fields.
