Part of church that's ramshackle, it's scary (8)
I believe the answer is:
sacristy
'part of church' is the definition.
('sacristy' is part of 'church')
'ramshackle it's scary' is the wordplay.
'ramshackle' indicates an anagram (I've seen this in other clues).
'its'+'scary'='itsscary'
'itsscary' anagrammed gives 'SACRISTY'.
'that's' acts as a link.
(Other definitions for sacristy that I've seen before include "Satyr (sic) found in church storage room" , "Where sacred vessels are kept in church" , "Room in church for vestments etc." , "Church robing room" , "Vestry" .)