  We are conducting a search for new gamma-ray binaries by making high
signal-to-noise light curves of all cataloged Fermi LAT sources and searching
for periodic variability using appropriately weighted power spectra. The light
curves are created using a variant of aperture photometry where photons are
weighted by the probability that they came from the source of interest. From
this analysis we find that the light curves of a number of sources near the
ecliptic plane are contaminated by gamma-ray emission from the Moon. This shows
itself as modulation on the Moon's sidereal period in the power spectra. We
demonstrate that this contamination can be removed by excluding times when the
Moon was too close to a source. We advocate that this data screening should
generally be used when analyzing LAT data from a source located close to the
path of the Moon.
