I just had a case where I spent 10 hours diagnosing. Pulling & testing each fuse, running light, finding a few bad bulbs. Which some have reported bulb was cause. In this case, it was not a fuse (although fuse keep blowing), bulb or socket.
It turn out to be, a clipped wire under the dash. Someone, installed a trailer brake assist, and clipped a factory wire. They left wire, just hanging without capping. No issue for 10 years, until wires moved to install other device. The clipped wire moved, and now touched bare metal, popping tail fuse.