Existing old ceiling surface light to be replaced with recessed can. I take down the light and look in the box and discover it's a MAJOR junction box. There's no fill violation, but it's right at the limit with two difference circuits branching off in there. The junction boxes attached to the cans are completely undersized for this. I think this is a 'no-go'.

editorial note:
I'm ashamed to admit it, but I'm pretty much a bookworm electrician. I do a lot better work than some lifers I've seen, but because I've had very little time with a master sparky I'm sure I do a lot of things the hard way. Not having the benefit of years of experience. Now that California has mandated the licensing, my time is up. I have no where near the required apprentice hours necessary for the test.