I've heard people quote G. Gordon Liddy who has said "i may not own any firearms (since he's a felon), but my wife sure has a whole bunch"
I think it is kind of a gray area. if the felon is the only one living there and there are guns, i think he would be in possesion. but if its a married couple or roomates, where one is not a felon, i would tend to think its ok.
thats my uninformed opinion. talk to a lawyer if you want to be really sure.