Sweet wine as alarm is switched (7)
I believe the answer is:
marsala
'sweet wine' is the definition.
(I've seen this before)
'as alarm is switched' is the wordplay.
'is switched' indicates anagramming the letters (letters switch places).
'as'+'alarm'='asalarm'
'asalarm' is an anagram of 'MARSALA'.
(Other definitions for marsala that I've seen before include "Dessert wine from Sicily" , "Alcoholic drink" , "Wine - as alarm (anag)" , "Sweet Sicilian wine" , "Fortified Sicilian wine" .)