Listen in with royal receiving a fake shock (6)
I believe the answer is:
earwig
'listen in' is the definition.
(earwig can mean to secretly listen to something)
'royal receiving a fake shock' is the wordplay.
'royal' becomes 'er' (abbreviation for Elizabeth Regina).
'receiving' indicates putting letters inside.
'fake shock' becomes 'wig' (shock can mean a mass of hair).
'er' going around 'a' is 'ear'.
'ear'+'wig'='EARWIG'
'with' is the link.
(Other definitions for earwig that I've seen before include "Aural appendage and head covering for an insect" , "flatterer" , "Close acquaintance" , "Pincered insect" , "Clawed insect" .)