@Della69 There are very few hosts, at least hosts on this forum, who consider it acceptable for hosts to enter without prior notice. Of course if there were an emergency situation- a burst plumbing pipe, a fire, they might need to, but it only takes a minute to text a guest to let them know the situation.
Some hosts feel justified in entering if a guest ignores requests to turn off lights, turn down AC or heat when not at home, but even that really shouldn't be done, although it's understandable that if a guest is just wasting resources, and ignoring a simple and reasonable request, a host doesn't want to end up with a higher electric bill than what the guest paid for the accommodation.
I once entered my guest's private bedroom when she wasn't home because there was a sudden downpour and I saw that she'd left the windows open. I didn't want her to come back to a wet bed, but I texted her immediately to let her know I'd done this. I was in and out of the room in about 15 seconds.
Guests most certainly should expect their privacy to be respected.