What do I do both parents are loosing their minds + spending $ everywhere? help

Both of my parents are have become hostile, combative, aggressive and lying. They are spending a lot of money on big purchases and after a few weeks or a month getting rid of it and buying more things because someone else has thought about it. My wife has been attacked physically and my mother screams like a mental patient with periods of blank stairs lasting hours. Her mother had it. My father is an electrical engineer but couldn't do a less than 30 min wiring task in over 26 hrs and still can't, he is constantly crying and praying to god that he doesn't want Alzheimer's and they are in denial completely. I am an only child and I haven't any idea how to help them especially since my father is a control freak severely. I love them and I do not know how to protect them from loosing everything to where there isn't money for a memory care facility. Is there a law to help me protect them from themselves . My wife was injured an we are waiting since I was transferred to another state for my job to find out if more damage was done to her hardware in her neck and spine.she is disabled and has been for 6 years. What advice can I get to save them and get them assessed due to their past three years of increasing illnesses since they are so much in denial and I do have a letter from my mother that shows her state of mind. My father is a big henderence to both of them getting car. Sincerely living and deeply scared for them the only child.