Caller sent to vault (6)
I believe the answer is:
cellar
'vault' is the definition.
(I've seen this before)
'caller sent' is the wordplay.
'sent' indicates an anagram (send can mean to excite or stimulate).
'caller' is an anagram of 'CELLAR'.
'to' is the link.
(Other definitions for cellar that I've seen before include "Storage space, for wine perhaps" , "Place for wine" , "Room at the bottom, maybe for wine" , "Underground area" , "Basement room, wine may be stored there" .)