This book is for sale by Dr. Akira Fujimoto, and it may be helpful.
A person possessed by a husband is generally called a ghost, and it seems to be classified as a type of hungry demon in Buddhism. Those in this situation want to save themselves, so they look for someone who seems to have a kind heart and ask for help. I have no idea what kind of person my husband is, but I think ghosts are kind people. So, you should be kind to them. They don't like it or dislike it, so they insist on themselves, “Don't do that, help me.” It seems that being afraid or scared won't solve it forever.
Now, the specific question of how to be kind is simple. Instead of trying to get scared of that ghost, it's better to say, “Please be happy.” You will encounter someone's kindness, and it seems that the ghost will bring joy to your heart and be able to get out of a difficult situation.
I think the details were written in Dr. Fujimoto's book “The Right Way to Make Memorial Service for Your Ancestors” (I think it was), so please read it. It's written so you can understand it. Also, I think it's easy to consult on the internet, so it might be a good idea to ask Seikyo-ji Temple in Yamaguchi by email etc.
Even from a general point of view, wishing for the happiness of others and wanting to bless those who are suffering should be fine without complaint. It's not that they don't like it; it seems that if you say sorry, you'll break out of the realm of suffering and go to a place called heaven. You can help ghosts that don't help people, and you can also accumulate good roots.