Do your turn signals and marker lights work reliably? If so, I would rule out a bad ground.
Brake switch could be bad. I have not heard of one going bad. Find it and jump the connection and check the lights. If they work, bad switch.
There probably a relay in the fuse box, I'd check it. Relays do go bad.
Was the fuse blown? If so, might be a broken wire and shorting out. Worst type of electric to diagnose, the wire could be damaged anywhere. I would start at the light and work forwards. Should be in a loom, look for damage loom first. Wires do fail within the loom. Squirrel or heat might have caused damage. Could be corrosion at a connector.
2012 Jayco X23B
2020 Ram Laramie 3500 SRW Air ride 50Gal fuel tank.
2007 Dodge Dakota Quad Cab (retired from towing)
Equal-I-zer 4-Point Sway Control