  We predict that the mesoscopic tensile force fluctuations in metal quantum
point contacts (nanowires) arise as a result of finite electric voltage on the
contact. They are due to reconfiguration of the electronic subsystem and are
correlated with the nonlinearities of the current-voltage characteristics of
the contact. The observation of the effect would directly confirm the recently
suggested "free-electron" mechanism of mesoscopic force fluctuations observed
in nanowires under deformation. The related magnetic susceptibility
fluctuations and role of topology of the wire cross section are discussed as
well
