Hat found in dark room, oddly (8)
I believe the answer is:
sombrero
'hat' is the definition.
(sombrero is a kind of hat)
'dark room oddly' is the wordplay.
'dark' becomes 'sombre' (I've seen this before**).
'oddly' indicates alternate letters.
The alternating letters of 'room' are 'ro'.
'sombre'+'ro'='SOMBRERO'
'found in' acts as a link.
(Other definitions for sombrero that I've seen before include "Large Mexican sun-hat" , "Mexican's hat" , "Hat for South American" , "Straw hat with very wide brim from Mexico" , "CLOTHING" .)