My mom and I live with my grandmother and she is now convinced that someone is smoking in the house. My mom doesn't smoke, and I don't smoke either. It has gotten to the point that I can't even go downstairs without her asking who's smoking upstairs. She calls me a liar and keeps saying not to tell her that my mom isn't smoking. I don't know what to do. She always looks out her window to see when we are coming and going and then she closes her door whenever she knows that my mom is home. What can I do? I don't know how to handle this anymore.