Answer by  
                                                                                          technogeek (6640)
                                                            
                          
                          
                                                          There is more than likely a short in the line for that breaker. Even though there is nothing connected to that breaker, if there is a short in the wire, the slightest vibration from your house will cause the wires to move and separate, causing the breaker to trip. Have an electrician check it out.