What should a male nurse wear to an interview?

I'm a new grad nurse and I was called today for an interview tomorrow. I've been looking over the questions and feel I will be okay with some practice, but I was worried about what should I wear tomorrow?

I know a suit is always the best option, but frankly as a new graduate my funds are low and my suit option is an ill fitting suit that I wore at a wedding 3 years ago.

I was planning on wearing slacks, dress shirt, and tie. For some reason that feels a bit under dressed to me, would wearing a cardigan be acceptable?

Thanks.
A cardigan is going to make you look less dressy, not more. A dress shirt, slacks, and a tie will be fine.