  We present a formulation of Einstein--Maxwell vacuum fields due to plane
fronted electromagnetic waves sharing their wave fronts with gravitational
waves. This is based on a recent geometrical reconstruction of plane fronted
wave fields by the authors which clearly identifies the cases in which the wave
fronts collide or do not collide. In the former case our construction suggests
an explicit example of a searchlight beam, accompanied by gravitational
radiation, which sweeps across the sky. This gravito--electromagnetic
searchlight and its properties are described in detail.
