Yep, the circuit breaker in the headlight sawitch is cycling, either due to an overload somewhere, or a set of high-output headlight bulbs that are drawing too much current. Have you swapped to a set of halogen bulbs or something similar recently? If there hasn't been any change associated with the headlights recently, look for a short in the dimmer switch. Those things live in a nasty environment, and they're subject to getting partial shorts. If the C/B in the switch has cycled very much, it could have damaged itself and you might need to replace the switch. It's there instead of a fuse to prevent total loss of the headlights- - - -they flash, rather than just going out in case of a short.
Jerry