  We show that magnetic fields have the potential to significantly enhance a
recently proposed light-shining-through-walls scenario in quantum-field
theories with photons coupling to minicharged particles. Suggesting a dedicated
laboratory experiment, we demonstrate that this particular tunneling scenario
could provide access to a parameter regime competitive with the currently best
direct laboratory limits on minicharged fermions below the $\mathrm{meV}$
regime. With present day technology, such an experiment has the potential to
even overcome the best model-independent cosmological bounds on minicharged
fermions with masses below $\mathcal{O} (10^{-4}) \mathrm{eV}$.
