My daughters 97 Avalon blows the brake light fuse about every other day.
I thought I'd eliminate some wiring as a troubleshooting procedure.
There is a connector block on the side next to the drivers foot.
I found the brake light wire at the connector and in the trunk. I cut
the wire at the connector and ran a new wire from the front to the
trunk, I also cut the wire in the trunk, and wired the new wire to the
brake lights. That leaves just a short old wire in the trunk going to
both the left and the right brake light.
The fuse opened again a couple days later.

Is there anything internal to the brake lights that could short to
cause the fuse to blow?

There is at least one other circuit run by that fuse, there is a shift
lever release (solenoid?) mechanism.
You must push the brake pedal to move the shift lever.

Any help?
Thanks, Mikek