OK, what does it say. I got mine 6 months ago and I don't remember exactly what it said. I do remember that, like every other pre-printed form that the government produces, it had a number (look for very small text at the bottom of the page, maybe).
If the questions are similar to the yes/no N-400 questions (e.g. "have you been cited or whatever, including traffic violations?") then that's the "Oath Letter".
The USCIS may be a lot of things, but I'm real sure they don't hand out prank forms to applicants. If it tells you to show up to take your oath, then it's probably correct