Early visitor to house after castle, say (7)
I believe the answer is:
postman
'early visitor to house' is the definition.
(a postman delivers letters early in the day)
'after castle say' is the wordplay.
'after' becomes 'post' (I've seen this before).
'castle say' becomes 'man' (castle is a kind of man).
'post'+'man'='POSTMAN'
(Other definitions for postman that I've seen before include "one delivers" , "Male to deliver mail" , "Mail deliverer" , "Chap with letters" , "No stamp needed, stangely, for this job" .)