  We look at a superposition of symmetric simple exclusion and Glauber dynamics
in the discrete torus in dimension 1. For this model, we prove that the
fluctuations around the hydrodynamic limit are described, in the diffusive
scale, by an infinite-dimensional Ornstein-Uhlenbeck process. Our proof
technique is an adaptation of Yau's Relative Entropy Method that is robust
enough to be adapted to other exclusion models. To cut the technical details to
a minimum, we assume that the process starts from a product measure with a
custom-chosen density, for which the solution of the hydrodynamic equation is
stationary. Although we prove fluctuations only in dimension 1, we provide an
estimate on the entropy production that holds for any dimension and a proof of
the Boltzmann-Gibbs principle that applies in dimension smaller than 3.
