CITROEN PICASSO EXCLUSIVE, 2005 MODEL REAR WIPERS?

THE REAR WIPER ON MY 2005 PICASSO HAS STARTED TO SWITCH ITSELF ON AT ODD TIMES. IT SEEMS TO BE AFTER THE BOOT HAS BEEN OPENED. WORKS FOR ABOUT ONE MINUTE, THEN STOPS, ONE MINUTE LATER IT STARTS AGIN, REPEATS THIS FOR AT LEAST 5 MINUTES. IGNITION SWITCHED OFF, KEY REMOVED. IT STARTS UP AGAIN AS I USE THE AUTOMATIC DOOR LOCK FACILITY TO LOCK OR UNLOCK THE CAR. DOES IT WHEN ENGINE RUNNING OR NOT. HELP PLEASE