Mislays husband in grotto, almost a disaster (5,5)
I believe the answer is:
close shave
'almost a disaster' is the definition.
(I've seen this before)
'mislays husband in grotto' is the wordplay.
'mislays' becomes 'loses' ('lose' can be a synonym of 'mislay').
'husband' becomes 'h' (abbreviation).
'in' is an insertion indicator.
'grotto' becomes 'cave' (I've seen this in another clue).
'loses'+'h'='losesh'
'losesh' placed within 'cave' is 'CLOSE SHAVE'.
(Other definitions for close shave that I've seen before include "Sharp razor helps with this" , "Danger narrowly averted" , "Almost a disaster" , "Narrow escape from disaster" , "result being not so hairy" .)