Last night we locked up downstairs & left my keys hanging still in the door as we usually do. When my partner left for work this morning his keys were hanging there in the door still locked but when going out & closing the front door to lock it he found my keys were hanging outside in the lock. There was no window open through the night where someone could of got in & both front & back door was locked before going to bed. How did my keys get outside !? Can't think of a logical explanation, driving me mad.