my two year old son has always slept right through the night and goes to sleep with his lamp on but now he has started asking for the main light on aswell as the lamp and cries if he doesnt get it on. i can turn it off as soon as he is asleep. but cant workout why hes started doing this. any help please

Has he had an incident related to the dark that has scared him?

Or something that has happened that he may just be thinking about whn he is alone in bed?