I'm going to snap after 4 years at the head of maintenance at my work and sarcastically apologize for how his life turned out compared to what mine will be
Why are you going to do this?
I want him to know how I feel.
If you have a problem you should be open and honest about it. You could get fired if it goes wrong and is taken in bad light.
I am only going to do it as a joke.
You should probably cancel your entire plan I don't see it ending well. If he doesn't take it as a joke you could lose your job like I said before. Maybe you can find a new job just incase?