Most "absurd laws" are a complete myth, or are simply archaic laws which have been repealed, which seemed to make sense long ago, but are quoted as if they still exist.
Others are bizarre, convoluted misquotes of something which may be perfectly legal, not prohibited, but not specifically referred to in law either.
A common one doing the internet rounds is "tropical fish saleswomen in Liverpool, England, may work topless."
This is bizarre and true, yet false. The law in England does not specifically forbid nudity or toplessness. It forbids nudity only if someone who sees it expresses that they feel offended. So if nobody expresses an offence, nudity is not a crime. Therefore any woman could conceivably go topless anywhere in England without charge. But the fact the law does not forbid it, is not the same as expressly calling for it. And no such national law exists, or a Liverpool bye-law. Complete urban myth.
Another amusing one is reputedly from a US city, I forget which one, saying that nobody must detonate a nuclear device in the city limits. Barmy. And most likely covered in sensible legislation relating to deliberately causing any explosion.