I assume the house belongs solely to your ex husband. (If it was jointly owned you would not be able to get Housing Benefit, even if you transferred your share to him.)
It is possible in some circumstances to get HB to rent from an ex-partner, but there has to be a proper arms length commercial tenancy agreement, and the local authority would want to look closely into the situation. It is probably best to enquire of their Housing Benefit Section.
Do remember as well that there are limits on the level of rent that HB pays - both in relation to the size of property and average rent levels in the locality. If the Local Authority accept the principle, you need to ask them for a pre-tenancy determination to find out how much rent they would pay.