I worked 2 years as a corrections LPN. It was pretty easy money, but it actually paid less than most hospitals around here pay. Not sure why, but the company I worked for had the contract for both the county jail and the county penal farm (same county), but the jail paid about $5/hr more than the penal farm. I was at the farm.
There was plenty of overtime. The inmates didn't bother me once they knew that I wasn't taking any crap off of them. They will test you and try to get under your skin, but they'll eventually leave you alone if they figure out that you're not going to play their games. I actually had more of a problem out of the guards and administration than out of the inmates.
You will lose your skills. As an LPN, you'll most likely just be a pill-pusher. At least here, they prefer RN's to work in the clinic and LPN's to work in the med room. But, either/or can work in either area by job description. I spent a lot of time working in the clinic, and you rarely find anything that requires much more skill than a well-defined BS meter.
Having said that, working in corrections is dangerous to your license. You will work with other nurses who have developed an institutional mentality. What this means is that they have developed an "us vs. them" mentality against the inmates. Many nurses who have been in corrections for a while eventually feel that all inmates are lying all the time, and will go out of their way to prove that an inmate is lying about an illness, when in fact the inmate may be telling the truth. This will get you hung up because you will either develop this mentality, or you will work alongside a nurse in the clinic who has this mentality, and you will be the one on the witness stand in court after an inmate dies from an illness that was missed because your coworker tried their best to prove that the inmate was faking that intractable seizure. Not that I have any experience being on the witness stand, but I have fought against nurses with this mindset in corrections, and eventually left corrections because of it.
I would never go back to corrections as full-time staff. I may do it later in my career for part-time money, but never as full-time staff. Too much liability. Also, once you're in corrections, it's very difficult to get out. Future employers see corrections on your resume, and they may believe that you've already developed the institutional mindset and may not have as much compassion as other nurses. I've heard this from several DON's. It takes a lot of convincing to make them believe otherwise.