I don't want an auto topoff system- it won't work with my setup and I'm not sure I'd go that route anyway- but I am looking for something that will

1) simply make some kind of noise when the water hits a certain level, to remind us to add water to the sump, or

2) actually shut the electricity off to my return pump if the water hits a certain level.

Either one will work, I guess option 2 is that much safer, option 1 probably simpler. I would like to hear what others might be using for this purpose. Either stuff you can buy or DIY solutions would be greatly appreciated!

Thanks!