Phantom post office disappearing when parcel post is deregulated? (8)
I believe the answer is:
'phantom' is the definition.
'post office disappearing when parcel post is deregulated?' is the wordplay.
'post office' becomes 'po'.
'disappearing when' is a deletion indicator.
'is deregulated?' indicates anagramming the letters (I've seen 'is deregulated' mean this).
'parcelpost' with 'po' taken away is 'parcelst'.
'parcelst' is an anagram of 'SPECTRAL'.
(Other definitions for spectral that I've seen before include "Ghastly" , "Like a colourful band" , "covering a range of colours" , "Spooky" , "Rap Celts for being ghostly" .)