What to do with a father who is up all night and sleeps all day?

My father lives live my brother and myself; we are his caregivers. He has started in the last two months sleeping during the day and roaming the house at night. He doesn't do anything dangerous other than keep us up. He has starting calling my name at 2:00 or 3:00 morning or later and waking me up yelling what should he be doing?

I know this part of his ALZ/Dementia and not much we can do. He does have prostrate issue so he gets up quite frequently and goes to the bathroom.

I really don't want to medicate him but I would love to get a good night sleep. I thought others may have this same issue?

Any help is appreciated.