Yeah LJ.......at 288 cubic inches that box will be big enough...........
NMDave.......I've got a couple questions........
the feed gfci is in another box.....the only device is the switch ?
What's that # 14 ground wire doing on the 20 amp circuit and what more is on that circuit/side of the garage....?
And the #10 side of the garage.....what's over there ?
Did the Inspector "Flag" you on this installation/box?
And just how big and use is this garage ?
If I had to gaze into my crystal ball......I'd say this box is really ugly and confusing......all extended from a single outlet......
Conduit and NM-B....Solid and stranded...# 14-12-and 10.......
If the Inspector-Man can't figure it out in a glance you're "screwed".........
Even without any box-fill issues I would break out the switch/porch light as a separate switch box......use conduit between the switch and J-box........OK, keep the NMB to the light....... and keep the J-box as a junction box only.........