I don't like the idea of putting in putty and drilling it out, but it wouldn't be the worst DIY hack that I have ever seen.
Honestly though, switching out the box is not a particularly big deal. Seriously consider getting up there and getting a good look at it and check out a couple of youtube videos. You can get an old work box and throw it up between some rafters in a few minutes.
I don't like the idea of putting in putty and drilling it out, but it wouldn't be the worst DIY hack that I have ever seen.
Honestly though, switching out the box is not a particularly big deal. Seriously consider getting up there and getting a good look at it and check out a couple of youtube videos. You can get an old work box and throw it up between some rafters in a few minutes.