  We consider Maxwell fields associated with any shear-free null geodesic
congruence on Minkowski or Riemannian background space-time. Bounded singular
loci of these fields are treated as particle-like formations, possess
"self-quantized" electric charge and undergo self-consistent time dynamics.
Complicated singular solutions of Maxwell (as well as related complex
Yang-Mills) equations can be obtained in a purely algebraic way using the Kerr
theorem.
