Every night it's some thing. Parents of kids under 5 know there is no "goodnight Hunny", smoochy smoochy & they scamper off to bed and not wake until 7 am. No. Our 2yo will open the door multiple times and will occasionally come upstairs.
I forgot I did this with Elizabeth. I stood by her door and waited her out. It's something that Super Nanny does and Dr Leman recommends. I was doing expert advice w/o consciously knowing it, hehe.
When E was young, still in the crib, she'd whine and I'd open her door, tell her to shush, and she'd be quiet. I did it too after she was in a big bed and she'd peek out @ night. I swear the kid thought I camped outside in her hallway all night.
So why didn't I remember this until just recently w/ #2? Because I have mommy brain and I can't finish a thought or recall anything.
Anyway ms F started having this prob of sneaking up the stairs at night....until mommy stayed outside her room a couple of nights and waited for that first door creek. Stern mommy voice, "Felicity, go back to bed." Door shut. Might happen once more, but not usually. First time scared her and she cried. Now she keeps her door closed and I listen to her song the alphabet or count.
It's not down to perfect yet. Sometimes this is still my 5 min post bedtime post.