Crazy about current employee (4)
I believe the answer is:
maid
'employee' is the definition.
(I've seen this before)
'crazy about current' is the wordplay.
'crazy' becomes 'mad' (synonyms).
'about' is an insertion indicator.
'current' becomes 'I' (symbol for electric current).
'mad' enclosing 'i' is 'MAID'.
(Other definitions for maid that I've seen before include "employee" , "- - -of-all-work" , "Damsel" , "Female domestic servant" , "daughter?" .)