  We present the discovery with WISE of a significant infrared excess
associated with the eclipsing post-common envelope binary SDSSJ
030308.35+005443.7, the first excess discovered around a non-interacting white
dwarf+main sequence M dwarf binary. The spectral energy distribution of the
white dwarf+M dwarf companion shows significant excess longwards of 3-microns.
A T_eff of 8940K for the white dwarf is consistent with a cooling age >2 Gyr,
implying that the excess may be due to a recently formed circumbinary dust disk
of material that extends from the tidal truncation radius of the binary at 1.96
Rsun out to <0.8 AU, with a total mass of ~10^20 g. We also construct WISE and
follow-up ground-based near-infrared light curves of the system, and find
variability in the K-band that appears to be in phase with ellipsoidal
variations observed in the visible. The presence of dust might be due to a)
material being generated by the destruction of small rocky bodies that are
being perturbed by an unseen planetary system or b) dust condensing from the
companion's wind. The high inclination of this system, and the presence of
dust, make it an attractive target for M dwarf transit surveys and long term
photometric monitoring.
