Caught on camera: Underwear-clad man sets Donald Trump yard sign ablaze in Platteville

PLATTEVILLE -- He was so determined to torch a Donald Trump yard sign -- he didn't even bother to put on pants.

It was all caught on camera.

The Wisconsin couple who put up the sign said they were shocked to find it destroyed.

When they checked their surveillance system, they found THIS:

One of their tenants is accused of setting the yard sign ablaze.

Police are investigating.

Meanwhile, the couple plans to erect an even bigger sign -- maybe even a billboard.