Volume in test all over the place: watch it! (2,3)
I believe the answer is:
tv set
'place watch it' is the definition.
I can't judge whether this defines the answer.
'volume in test all over' is the wordplay.
'volume' becomes 'v' (abbreviation for volume in book titles).
'in' is an insertion indicator.
'all over' says the letters should be written backwards.
'v' placed into 'test' is 'tesvt'.
'tesvt' written backwards gives 'TV SET'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for tv set that I've seen before include "'Goggle box (2,3)'" , "Goggle-box" .)