My aunt is creating an unsafe environment for my grandmother to live in. What should we do?

My grandmother let her daughter (my aunt) move in with her years ago. My aunt is a classic hoarder. My grandmother is a very neat person and that alone causes her stress. Recently, my grandmother had a stroke. The rest of the family has concerns about her living environment being unsafe because of the clutter. It is her home. In the past we have all offered to help clean up, but my aunt won't let us and my grandmother doesn't want to upset her. While my grandmother is hospitalized, my aunt has locked us out of the home, she lives there but it is legally not hers. What are our options and what do you recommend.