  We present optical and near-infrared spectroscopy of WISEA
J061543.91$-$124726.8, which we rediscovered as a high motion object in the
AllWISE survey. The spectra of this object are unusual; while the red optical
($\lambda >$ 7,000 \AA) and near-infrared spectra exhibit characteristic TiO,
VO, and H$_{2}$O bands of a late-M dwarf, the blue portion of its optical
spectrum shows a significant excess of emission relative to late-M type
templates. The excess emission is relatively featureless, with the exception of
a prominent and very broad Na I D doublet. We find that no single, ordinary
star can reproduce these spectral characteristics. The most likely explanation
is an unresolved binary system of an M7 dwarf and a cool white dwarf. The flux
of a cool white dwarf drops in the optical red and near-infrared, due to
collision-induced absorption, thus allowing the flux of a late-M dwarf to show
through. This scenario, however, does not explain the Na D feature, which is
unlike that of any known white dwarf, but which could perhaps be explained via
unusual abundance or pressure conditions.
