Comfortable position that's safe to hold at home (8)
I believe the answer is:
sinecure
'comfortable position' is the definition.
(an undemanding but lucrative job)
'safe to hold at home' is the wordplay.
'safe' becomes 'secure' ('secure' can be a synonym of 'safe').
'to hold' is an insertion indicator.
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
'secure' enclosing 'in' is 'SINECURE'.
'that's' is the link.
(Other definitions for sinecure that I've seen before include "Undemanding job" , "position needing little effort" , "Office that involves minimal duties" , "Official job with little or no work" , "Very lucrative post" .)