Job easily done at home, firm admits (8)
I believe the answer is:
sinecure
'job easily done at' is the definition.
'sinecure' can be an answer for 'job' (I have seen 'Cushy job' mean 'sinecure' so perhaps 'job' could also mean 'sinecure'). I'm unsure of the 'easily done at' bit.
'home firm admits' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'firm' becomes 'secure' (similar in meaning).
'admits' is an insertion indicator.
'in' placed within 'secure' is 'SINECURE'.
Can you help me to learn more?
(Other definitions for sinecure that I've seen before include "Official job with little or no work" , "A job that pays well for little work" , "Very lucrative post" , "Paid job involving little or no work" , "Office that involves minimal duties" .)