Is there any legal obligation to act when you receive court papers by mistake, especially if it could lead to an arrest warrant for someone else?

What makes some medical students prefer judgment tests over memorization tests, or vice versa, in their exam preparation?
Will the new Trump-hating Congress now ban all of Trump's mega projects? Will Trump's triumphal arch, his cheesy White House Ballroom, or the Trump-class battleships be the first to go? What else will get canceled by Congress?