ford focus tcdi 1.8 tcdi?

car battery has been flat on arrival home from 2 week holiday,i checked everything was switched off before i left this has happend once before,i have just noticed that above the cigarette/power outlet the little drawer was open slightly and that when i closed the drawer fully a light around the power outlet went off,this light is hard to spot can you tell me if this is right,that the drawer is a switch,seems daft but there you go.