I am trying to hang a set of blinds. I have one bracket on the left screwed into the wall tight but the other on the right is giving me trouble. I don't have anything to screw into apparently. I looked behind the wall and all the only thing to screw into is vinal siding. I got the bracket on the wall but it's obviously loose and won't hold the blinds. If I use the middle support bracket, it looks like it might screw into a stud. Will that be enough or do I have to still find a way to secure that right bracket? Any ideas are helpful.