Person left doing electrical work outside (9)
I believe the answer is:
earthling
'person' is the definition.
(earthling can mean a human being)
'left doing electrical work outside' is the wordplay.
'left' becomes 'l' (common abbreviation).
'doing electrical work' becomes 'earthing'.
'outside' indicates putting letters inside.
'l' inserted into 'earthing' is 'EARTHLING'.
(Other definitions for earthling that I've seen before include "Man of the world" , "Human being (sci-fi)" , "sci-fi character" , "man so to be called from space?" .)