A light sleeper will always be close to it (7,4)

'a light sleeper will always be close to it' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'light sleeper will always be close to it' is the wordplay.
I cannot quite understand how this works, but
'light' could be 'lamp' (lamp is a kind of light) and 'lamp' is present in the answer.
'be' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This explanation may well be incorrect...

Can you help me to learn more?