Learn English – Origin of “Every dollar you spend is a political act”

There is also another slightly different version of this phrase, which is believed to pre-date your version:

Nuttier than a sh*thouse rat.

also

Nuttier than a sh*thouse mouse.

It is intended as a pun on nuttier, since nuts are hard to digested they are likely to show up in the feces - which obviously end up in the sh*thouse. Since you can also be "nuts" I believe it changed later to "crazier".

The short version is: Use quotation marks only if you are quoting someone's actual words. If you are not quoting someone's actual words, do not use quotation marks. There is no parenthetical you can add to correct for this.

In an apocryphal quote, you are quoting the actual words that are attributed to the person; for example: "I cannot tell a lie" can be quoted and attributed to "George Washington (apocryphal)". If there was a definite source for the shortened version, you could list that person's name: "Play it again, Sam" could be attributed to "Woody Allen (paraphrasing Humphrey Bogart)".

But if the paraphrase is not part of someone else's quote, you can't put it in quotation marks; in formal writing, this will be seen as sloppy; in academic writing, dishonest. Instead, you need to put it in a sentence. "Abraham Lincoln said that we got here eighty years ago" is appropriate. "We got here eighty years ago." --Abraham Lincoln (paraphrased) is not.

Depending on the specific quote you want to use, you might be able to get away, in informal writing, with an (attributed). For example: "Play it again, Sam" -- attributed to Humphrey Bogart. Who it's attributed to him by can remain unsaid. Or, if the paraphrase is close enough, you may be able to "fix" it with brackets and ellipses: "Play it [again], Sam."

But much as I hate to say it, the best solution is to use a different quote. Consciously perpetuating a misquotation, no matter how you dress it up, will lead to mistrust in your audience.