I find your choice of context odd if you particularly want to use "misplaced faith". I might expect it to be used to refer to believing wrongly that someone can be relied upon.
John: I need to be at the airport by 4am.
Jane: How are you going to get there?
John: I'm pretty sure Dave will drive me.
Jane: Hah! That's a fine example of misplaced faith.
John: Why do you say that?
Jane: I've asked him five times to drive me somewhere early in the morning. He always refuses.
People have misplaced faith that politicians will do the right thing.
Student or Learner