  We investigate the dynamics of a three-state stochastic lattice gas,
consisting of holes and two oppositely "charged" species of particles, under
the influence of an "electric" field, at zero total charge. Interacting only
through an excluded volume constraint, particles can hop to nearest neighbour
empty sites. Using a combination of Langevin equations and Monte Carlo
simulations, we study the probability distributions of the steady-state
structure factors in the disordered phase where homogeneous configurations are
stable against small harmonic perturbations. Simulation and theoretical results
are in excellent agreement, both showing asymmetric exponential distributions.
