My dad ran five laundromats at the same time. As a boy, I was forever handing him tools and fetching supplies. If he wasn't replacing the transmission on a washer he was swapping out the solenoid. The most frequent repair on a wash machine back then was the boot. That's the rubber doo-hickey that kept the water in the tub. You knew the boot was bad if there was water all over the floor. If dad replaced one boot, he replaced a thousand.
When a transmission went out, dad knew he should really replace the boot at the same time; the process is just as complicated. If you do it right, you only have to do it once. But for dad, that was sometimes the road less traveled. That's good enough for now, he'd say.
You can do that when you own a laundromat. You can't when you work in healthcare.
If you're a healthcare manager, your most valuable "machines" are properly managed human beings. If they're run down or not properly maintained, it always threatens patient care, or at least your patients' perception of their care. So when a repair is required, it can't be just "good enough for now." Fixes have to be permanent.
If your staff's morale is plummeting because you have a liability on staff, you can get him up and running for a week or two with a formal reprimand. But he'll get over it and wreak havoc on morale again. You'll be right back where you started. Better keep the mop out.
But if you invest in a permanent fix---setting him down, detailing what exactly constitutes unacceptable behavior, openly seeking his suggestions, offering your support, and establishing expectations and consequences he can trust will be implemented---one of two things will happen.
1) he'll return to service and perform flawlessly, never requiring your attention again.
2) you'll need to consider the boot.