I did get advice from the previous thread. The box that spans the joists seemed like a good idea. I was restating the problem to see if a simpler solution existed.
[Moderating]
Please don’t start multiple threads on the same subject. I’ve merged the two threads.
Colibri
General Questions Moderator
I’d be wary of using an old work box to hold a light fixture in a ceiling, even if the previous fixture *hadn’t *already fallen out of the ceiling.
there isn’t a simpler solution than back mounting a metal box if you have a wood board over the top in good condition. measure the distance from the lower edge of the ceiling to that board for the depth of box.
I use those boxes (the blue ones with the little wings) for outlets and switches. I can’t imagine using them for anything that’s going to hold any kind of weight.
If the ceiling joist is right there, just move the hole over a bit and use the box I showed you before. It’s meant for fans and it mounts over the joist.
Old work boxes have their uses, but I would screw a metal box to the joist.
As recommended I drilled two holes into the box and used two wood screws to attach it to the joist. It is much more stable than the original. Put up the light I bought. Took down the light I bought. Too small. Too ugly. Does not cover the hole in the ceiling. The box is up so strongly that switching out would be no trouble at all.
Thanks for the extensive good advice.
You could use a ceiling medallion to hide the hole in the ceiling (although it won’t help with the ugliness of the fixture you bought).