Wanting to work PRN in ER

I work in a surgical progressive care unit for heart surgery patients. It is a critical care unit and while we rarely have intense emergencies we do have them at some times and I am very thankful that those are few and far in between.
However, I love being able to help in an emergency situation and feel like I can remain calm in the middle of an emergency. I love my unit and the people I work with.
My question is, is there any ER nurses that can give me an insight on their unit? I would love to be able to stay on my unit and maybe see if there is a part time or PRN position available in the ER, but I don't want to make a hasty decision and end up regretting it later.
Thank you