Unnecessary quote marks are kind of bugging me

I’m confused. Is the game not really tonight?

Dear sign-maker, forgive me for being a grammar nerd here, but is the game tonight or not? When people use quote marks like this, there are a couple of possibilities:

1. It’s a quote. Did someone actually say the word “tonight” and the sign-maker felt the need to attribute this quote on the sign? Perhaps we have an overzealous journalism student who is a stickler for always quoting his source, dammit.
2. It’s an attempt to communicate some degree of uncertainty, as in, “The game is ‘tonight,’ which of course means we have no idea if it’s tonight or not.”
3. It’s a display of sarcasm, as in, “Oh, riiiiight the game is ‘tonight’ … yeah (scoff), like that’s gonna happen.” (Note: This version, which is the most irritating, often is accompanied by “air quotes,” meaning that in 34 states you legally can punch them in the face.)
4. The quote key got stuck. (Not very likely.)
5. Those ain’t quote marks, they are the vicious claw marks made by the fightin’ Lake Travis Wildcats! Whoop! (Not likely, as the mascot actually is a Cavalier).
6. Sign vandals with a spare role of No. 6 Jet-Black Vinyl and a portable high-pressure Viking vinyl steam-iron added the quote marks on a ridiculously wild dare from the English Department. (This scenario gets my vote. Those English Department people can get pret-ty nutty.)