Hi. Hope somebody can help. Using a dry box outside i have put new outdoor led xmas fairy lights up. set up is ext lead from garage to dry box (garage power linked to house by armoured cable, garage has own consumer box). to manage these lights i have a cheap status mech plug timer inside garage where ext lead plugs into. lights went off at 9pm as set by timer. then at 2am the rcd trips the mains ring in the garage and house. Then next night same again but 1am. have now disconnected the lights and unplugged the timer. Can anybody suggest what may have happened? I suspect dodgy mech timer but unsure if this would trip the breaker. this has never happened having lived here for 10 years.