Instruction from shooter perhaps at Caerphilly? (3,6)
I believe the answer is:
say cheese
'instruction from shooter' is the definition.
The definition suggests a singular noun which matches the answer.
'perhaps at caerphilly?' is the wordplay.
'perhaps' becomes 'say' (both can mean 'for example').
'at' is a charade indicator (letters next to each other).
'caerphilly?' becomes 'cheese' (I've seen this before).
'say'+'cheese'='SAY CHEESE'
Can you help me to learn more?
(Other definitions for say cheese that I've seen before include "Water feature" , "Show your teeth" , "Term used by photographer" , "Photographer's phrase" , "Traditional photographer's request" .)