T.H.
My son is 7 yrs of age also and he some how has always beens scared of the dark we have fluoresent light bulb in his closet. We've always kept them on all night for him. He does slip into are bed often and we just let him because we know it will blow over soon. So just make him feel safe for a little bit and he will want to be a big boy again. Something triggered that fear, also when he does feel comfortable to go back in his bed tell him that he can have the door open to make him feel even safer.
We usually too, when my son falls asleep we try to put him back into his bed and sometimes he totally forgets that he even was scared.
I hope this helps.
T. H.