  We study a scale invariant $SU(2)\times U(1)_Y \times U(1)_s$ model which has
only dimensionless couplings. The shadow $U(1)_s$ is hidden, and it interacts
with the Standard Model (SM) solely through mixing in the scalar sector and
kinetic mixing of the U(1) gauge bosons. The gauge symmetries are broken
radiatively by the Coleman-Weinberg mechanism. Lifting of the flat direction
results in a light shadow Higgs or "scalon", and a heavier scalar which we
identify as the SM Higgs boson. The phenomenology of this model is discussed.
It is possible that shadow Higgs boson can be discovered in precision $t$-quark
studies at the LHC. The conditions that it be a dark matter candidate is also
discussed.
