So bought this house about a month ago, and the girlfriend wanted to swap a light fixture with a ceiling fan. No worries, I go get a ceiling fan support beam from the hardware store to install in the previous light fixture box to support it and get to work.

After pulling out the light fixture junction box though I'm met with a 2x4 that covered about 75% of the junction box hole that it was screwed into. It's not perpendicular to the support beams though like one should be to add support but parallel and with no connection to the support beams that I can see.

Between the stud finder I had and an endoscope I got at harbor freight, I put together what I think is going on. I drew a rudimentary sketch of what I see going on where red is normal support beams, yellow is the rogue 2x4 the shallow junction box was screwed into, and green is an even more random 1x3 it looks like, maybe connected to the 2x4, couldn't say for sure.I drew a rudimentary sketch of what I see going on where red is normal support beams, yellow is the rogue 2x4 the shallow junction box was screwed into, and green is an even more random 1x3 it looks like, maybe connected to the 2x4, couldn't say for sure.

Is there a reason they put that 2x4 up the way they did but with no tie in to the joists? The light was actually holding all it's weight on the hook in the picture which appears to be bolted into the joist which makes sense. So there's no need to have any support in this junction, but if you did wouldn't you have to tie it into joists?

And then for the ceiling fan install, is there any reason I can't just cut out the section of the 2x4 to mount the ceiling fan support tied into the joists? I think I'll have to in order to get it in correctly and I can't see a reason I shouldn't.