  We investigate the reach at the LHC to probe light sterile neutrinos with
displaced vertices. We focus on sterile neutrinos $N$ with masses $m_{N} \sim $
(5-30) GeV, that are produced in rare decays of the Standard Model gauge bosons
and decay inside the inner trackers of the LHC detectors. With a strategy that
triggers on the prompt lepton accompanying the $N$ displaced vertex and
considers charged tracks associated to it, we show that the 13 TeV LHC with
$3000$/fb is able to probe active-sterile neutrino mixings down to
$|V_{lN}|^2\approx 10^{-9}$, with $l=e,\mu$, which is an improvement of up to
four orders of magnitude when comparing with current experimental limits from
trileptons and proposed lepton-jets searches. In the case when $\tau$ mixing is
present, mixing angles as low as $|V_{\tau N}|^2 \approx 10^{-8}$ can be
accessed.
