Replace it with one of the same size. If the clicking continues you are drawing too much current through that circuit. If not it was a weak breaker.
If it clicks with the new breaker look at the loads on the circuit to see if you have added a new load that was not considered when built. If no new load you may have a short in the wiring, not that likely but it is possible.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles