While many Super User Agreements will contain common language/content, I'd strongly recommend at least building your own, if you do get one shared by all means take a look over it and pick it apart but I wouldn't use it un-edited.
Each community by it's nature is different and will have different requirements, you may want or expect different things from your Super Users and so it is important that you go through the process by identifying and outlining the objectives for your Super User programme to ensure that any agreement supports this.
A Super User Agreement has to be well thought out as Super Users need to understand any expectations of the programme without any ambiguity and at the same time you need something that allows you to effectively manage your Super Users if they deviate or become difficult.
I'm not saying that it should be full of legalese or something like a Terms of Service document for iTunes, but it's always worthwhile building your own agreement out ensuring you cover for any potential changes you might want to explore in the future with your community and the roles that Super Users may take on as the community grows and evolves.
I'd also point out that the Agreement goes both ways and should include from your side the type of support including any expectation setting you will have with that group. Super Users need to understand as part of the programme what you will provide them, it's often good to cover this off but not extensively. Allow yourself room to grow with this and start off small, that way if the programme expands anything else you do to support the Super Users is a bonus on top of their expectations which is always pleasant.
@KathleenJo I completely understand, if only it was that simple.
However what I will say is that it's much harder to update and change the Super User Agreement once you've set it in place and have users onboard.
By all means do look at any examples that are shared to get ideas, this community will offer a wealth of advice and expertise on different aspects based on experience so hopefully that will help ease the process a bit for you.
If you have any questions in relation to what to put into a Super User agreement just let us know, but knowing your own goals for the programme and what you want to get out of it is the best place in my opinion to start, if you can write that down or map that out it'll help get the ball rolling and hopefully steer some of the questions.
You'll have the usual generic stuff though around certain behaviours, activity which is great so you can copy that from others, but the extra stuff around that is what sets the programme up and really gets it going.
Great advice from @RobertT. Although he wasn't itemizing all the things that should be covered, I can't resist the opportunity to mention that one item that sometimes is not included in your published rules about the program and definitely should be, is that membership is invitation only and time limited, perhaps six months, but no more than a year. Include some subjective requirements such as "helpful to to other community members" and "shows a positive and welcoming attitude" to give you flexibility in not inviting certain people back, as well as a discussion point for re-inviting in the future. Hopefully, none of this is necessary, but unfortunately, I have seen multiple community managers over the years need the flexibility this provides to continue to manage a positive and helpful super user program.