The ballot drop boxes in Washington and Oregon both have fire suppression systems that are designed to activate when the temperature inside reaches a certain point, coating ballots inside with a fire-suppressing powder.
For unknown reasons, the system failed to prevent the destruction of hundreds of ballots in Vancouver, just across the Columbia River from Portland.
The full plan is detailed here: https://www.thenation.com/article/politics/little-secret-trump-johnson-election/.
Basically, they just need enough States to withhold submitting valid slates of electors, which are due on Dec 11th. If that doesn’t happen, and it lowers the amount of electoral college voters enough so no single candidate has a majority, then the US House gets to decide.
In other words, we’re fully reliant on GOP controlled States doing the right thing. We’re fucked.