>but aren't interested in mirrors
I have seen cats hissing at their own mirror image when it's a large enough mirror that reaches down to the ground. Also it might be that if the cat recognizes it's self in the mirror that it looses interest.
>They also have zero understanding of computer screens
If you show them video that was recorded low to the ground, from a similar point of view they would have, they get really into watching screens.
>It would be more fun if I could teach cats about light switches
You can do that, you just have to make switches that grab their attention, you know that switches we designed look tempting for humans and invite us to touch them... You have to do design with cat cognitive ergonomics in mind, cats like pull on strings with fluffy things attached to it, they also like to shove tiny objects with their paws, so a long sideways mounted paddle-switch with a ball on the end, near to the ground, would probably also work.