Shotgun or Troubleshoot...a dilemma
On the sketchy information given ... the problem could be anywhere in the circuit. It could be the CB has aged (corrosion or sensitized?), wiring incorrectly sized for load, loose connection, wire corrosion, or an appliance failing. Depending on your level of electrical knowledge I would suggest either of the following courses of action. 1. Shotgun approach - a. remove AC power b. check for corrosion of CB or wiring c. replace CB2. Troubleshoot ... 1. determine AC load with ammeter... i.e. is it a valid CB trip? a. yes, determine current draw of each appliance to and develop a AC appliance usage matrix b. no, remove AC power replace CB