  We present a wormhole solution in four dimensions. It is a solution of an
Einstein Maxwell theory plus charged massless fermions. The fermions give rise
to a negative Casimir-like energy, which makes the wormhole possible. It is a
long wormhole that does not lead to causality violations in the ambient space.
It can be viewed as a pair of entangled near extremal black holes with an
interaction term generated by the exchange of fermion fields. The solution can
be embedded in the Standard Model by making its overall size small compared to
the electroweak scale.
