Asked to remove case and reveal secret contents of closet? (8)
I believe the answer is:
skeleton
'secret contents of closet?' is the definition.
(as in the phrase 'skeletons in the closet')
'asked to remove case and reveal' is the wordplay.
'to remove case' indicates the central letters (letters which encase the word are removed).
'and' means one lot of letters go next to another.
'reveal' becomes 'leton' (synonyms).
The centre of 'asked' is 'ske'.
'ske'+'leton'='SKELETON'
(Other definitions for skeleton that I've seen before include "Possibly key" , "Internal framework" , "Bony structure" , "Framework, outline" , "one doesn't want found in cupboard" .)