  We consider the problem of electron transport across a quasi-one-dimensional
disordered multiply-scattering medium, and study the statistical properties of
the electron density inside the system. In the physical setup that we
contemplate, electrons of a given energy feed the disordered conductor from one
end. The physical quantity that is mainly considered is the logarithm of the
electron density, $\ln {\cal W}(x)$, since its statistical properties exhibit a
self-averaging behavior. We also describe a {\em gedanken} experiment, as a
possible setup to measure the electron density. We study analytically and
through computer simulations the ballistic, diffusive and localized regimes. We
generally find a good agreement between the two approaches. The extension of
the techniques that were used in the past to find information outside the
sample is done in terms of the scattering properties of the two segments that
form the entire conductor on each side of the observation point. The problem is
of interest in various other branches of physics, as electrodynamics and
elasticity.
