Well, ok it wasn't a creaking door. It was a loud-sound-when-you-opened-it door.
Actually, it was a terrible sound. Like a echoing hallow ripping sound.
(This does not go well with nap time. Even if it doesn't wake up baby, it gives mom wake-up-baby-anxiety.)
So I'm not sure how common this problem is, but I'm gonna show you the simple fix.
I thought at first it was just the top of the door rubbing on the door frame. So I set forth to fix it by sanding down the top edge. But the noise was still there after all that work.
So after opening and closing the door, while watching very closely (standing on a chair) I saw the problem.
We have the cheap hallow plain doors at our house. And I didn't relize it, but they are even cheaper than I thought because there is veneer on the front (I'm not even sure what the veneer is adhered to, its kinda crazy.) And that veneer was the issue.
It was coming unglued just enough to grab at the door frame every time it was opened. And the noise would rattle around in that hallow door and make an awful ruckus.
(You can see the crack right there in the photo.)
My mom was around the day I tried to sand it, and gave me THE best idea. Just stick some tape on it.
So I did.
I took a piece long enough to cover the crack, ran it along the door's edge and wrapped the extra width around the front and back sides. It's so inconspicuous (which is perfect) that it doesn't show up in photos.
(Cut that top part off, and you can't see it anymore!)
And now the door opens silently!!
Naptime has been saved! (For basically free!)