Tell them why you are interested in working for their facility and that particular unit
I'm a psych nurse at heart and the last one I went to, when the nurse manager asked me why oncology, I know I came off really fake. I intereviewd for my first psych job 2 days ago and it was a lot more natural to tell the nurse manager why I want to work in psych.
Be prepared for on the spot mini interviews with the usual interview questions.
I was asked
How do you handle stress
What is your weakness
Why should I hire you vs all the other applicants here
What would your last boss or instructors say about you
What things do you think you need to improve on