Shock about secretary turning on one fired in the office? (6,3)
I believe the answer is:
staple gun
'one fired in the office?' is the definition.
(device used in an office)
'shock about secretary turning on' is the wordplay.
I cannot quite understand how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
'on' could be 'leg' (cricket term, fielding positions) and 'leg' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for staple gun that I've seen before include "Tool for inserting fasteners" , "One that fires those fixing" .)