I'm concerned about my Mom living alone

Your concerns are valid. A senior whose house is overly cluttered, or filthy is an unsafe environment for them. The problem is convincing your mom of that! She probably sees letting someone come to clean as a loss of her independence. There is no easy answer. This article may give you some ideas on dealing with your mom:
https://www.agingcare.com/articles/how-do-i-get-dad-to-move-out-of-his-cluttered-unsafe-home-133954.htm