The Zoeller M267 mechanical switch is built into the pump. If you're fairly mechanical, it's not that difficult to replace. The hardest part might be unscrewing the screws that hold that housing together. Here is the replacement switch: https://www.sumppumpsdirect.com/Zoeller-004740/p8471.html
We do also recommend replacing the gasket, which you can find here: https://www.sumppumpsdirect.com/Zoeller-267007/p16469.html