  We formulate a set of naturalness criteria for sterile neutrinos (\nu') to be
light, needed for reconciling the LSND neutrino anomaly with the other neutrino
data. A light sterile neutrino becomes as natural as the light active neutrinos
if it carries quantum numbers of a chiral gauge symmetry broken at the TeV
scale. The simplest such theory is shown to be an SU(2) gauge theory with the
\nu' transforming as a spin 3/2 multiplet. We develop this model and show that
it leads naturally to the phenomenologically viable (3+2) neutrino oscillation
scheme. We also present next-to-minimal models for light sterile neutrinos
based on a chiral U(1) gauge symmetry.
