  We study a trial wavefunction for an interstitial in a Wigner crystal. We
find that the electron correlations, ignored in a conventional Hartree-Fock
treatment, dramatically lower the interstitial energy, especially at fillings
close to an incompressible liquid state. The correlation between the
interstitial electron and the lattice electrons at $\nu <1/m$ is introduced by
constructing a trial wave- function which bears a Jastrow factor of a Laughlin
state at $\nu=1/m$. For fillings close to but just below $\nu=1/m$, we find
that a perfect Wigner crystal becomes unstable against formation of such
interstitials. It is argued that conduction due to correlated interstitials in
the presence of weak disorder leads to the {\it classical} Hall resistivity, as
seen experimentally.
