Troublemaker in gaol sadly supporting house (8)
I believe the answer is:
hooligan
'troublemaker' is the definition.
(I've seen this before)
'in gaol sadly supporting house' is the wordplay.
'sadly' is an anagram indicator.
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'house' becomes 'ho' (abbreviation for house**).
'in'+'gaol'='ingaol'
'ingaol' with letters rearranged gives 'oligan'.
'oligan' after 'ho' is 'HOOLIGAN'.
(Other definitions for hooligan that I've seen before include "Tough" , "Violent young troublemaker" , "Rough, lawless person" , "Young rough" , "Ruffian, noisy troublemaker" .)