Mom is seeing and hearing people who are not there at all. Any advice?

Seeing and hearing people who are not there is called hallucinating. Hallucinations are very real to the people who have them. It is almost never possible to reason or argue someone out of them.

Hallucinations are often part of dementia. But they can also be caused by infections, such as urinary tract infection (uti). It is important to get a medical checkup and determine if there is a treatable cause for the hallucinations.

Try not to argue with her about this. Accept that what she sees is real to her. If what she sees and hears disturbs her, try to comfort her and then change the subject. ("That person down by the mailbox is probably just lost. He is not going to get in here. We have very good locks. Speaking of the mailbox, have you seen the new magazine that came today?")

Re read my post that is not what I said. Spiritual visitors are not the same as hallucinations. Hallucinations are not a sign of imminent death and can happen at any age for many reasons. Spiritual visitors are often seen by the dying patient, and I stress the dying patient, and that is one who has other signs of approaching death.
I was a hospice RN for some ten years and the very last thing I would ever do is tell people such rubbish that would alarm caregivers. I certainly resent your implication that I put up unsubstantiated information. I merely share my experiences and those of my collegues over many years of experience.
I stress that spiritual visitors are usually very comforting to the patient and they often recognize them for what they are
My intention is not to start a fight. Clearly your wife had a different experience from me but I stand by my original post.

Jeanne is correct. My mother, who never had dementia, had very vivid hallucinations when she had her hip replaced. I am 100% confident they were hallucinations, and she was and remained 100% confident that they were real. She was a very smart lady, so they must have been quite convincing to fool her.

I just stopped discussing it with her, and she never had any more.

So humor her and reassure her. Don't try to convince her she is wrong.

Gosh, I asked Grampa all about the things he saw. He saw movies on the garage, birds flying with long sticks, visitors in the living room. We would laugh with him. He had kidney failure, the toxins produced vivid hallucinations.
Another Grandmother, unfortunately, saw a man in a black cape with a big knife at her door. She had to go to a secure facility.
As long as the images are comfortable, allow her to enjoy them.

My 87 year old mother had hallucinations after she broke her hip and again after another stroke, hearing her mother calling her, seeing dogs and my father who passed 15 years ago, After any anesthetic she had to be strapped down, screaming for someone to call the cops as she was being murdered. It faded eventually. On her notice board in the NH there's a picture of a cat and the latest is that when she goes to heaven she's going to be with that cat and call it Kharma. Okey dokey. Perhaps it's just the body's way of coping with trauma.

I agree, it is not an imminent sign of death. It's a change in the brain function where memory and reality overlap and can't be sorted out. My Grandpa saw dancing girls for many years. He was one of the lucky ones.

My mom sees and hears Johnny Cash he is driving her crazt the same song and tune al the time

Wabdalee, my Mom kept hearing 'amazing grace', I looked it up on the internet and it's called audio hallucinations, connected with hearing loss.

on one of my moms worst days she was argueing with several different people around her. at one point she looked up towards the ceiling and told a guy to get out of here, you dont even have a head. that in itself wasnt funny but the cynical grimace on her face was priceless. you dont pee on my moms back and tell her its raining. lol , she was as analyitcal as the fbi.

Capt you Mom was a very special person. I wish I had known her.