To dream of a prison warden may represent feelings that obligations or debt needs to be carried out completely. You or someone else that feels nothing should feel good until justice is perfectly served. A prison warden may also reflect your feeling about someone else being a "stick in the mud" about fulfilling a punishment or debt perfectly.
Negatively, a prison warden may represent an unwillingness to let anyone off easy. Feeling that a punishment has to be carried out until the very end.