Choice to turn it on after work (6)
I believe the answer is:
option
'choice' is the definition.
(I know that choice can be written as option)
'turn it on after work' is the wordplay.
'turn' is a reversal indicator.
'after' says to put letters next to each other.
'work' becomes 'op' (common abbreviation for 'opus').
'it' in reverse letter order is 'ti'.
'ti'+'on'='tion'
'tion' after 'op' is 'OPTION'.
'to' acts as a link.
(Other definitions for option that I've seen before include "The choice of taking or leaving" , "Something choosable" , "Potion (anag.)" , "Alternative for choice" , "Something that may be chosen" .)