My father is 85, lives alone. He sleeps on and off through the day and is upseveral times at nite. Should we intevene in some way?

Not enough information about his diagnosis and habits to provide an informative answer to your question. I don't see anything listed on your profile either...

Your father may need some sort of organized activity if he is bored and needs some socializing.

I don't see anything abnormal with periodic naps and periodic night waking. If I was retired and bored that could be me.

Can you give some more background so we get some sense of why you are worried?