Combine in slow cooker: evaporated milk, paprika, salt, egg, butter and cheese; stir.
Cook on high for 1 hour.
Nearing the end of the hour bring a large pot of lightly salted water to a boil. Add macaroni and cook for 7 to10 minutes or until the macaroni is al dente (pasta should not be done - it needs to be chewy) and drain.
Stir cooked macaroni into cheese sauce, reduce temperature to low and cook for 2 to 4 hours or until ready to serve.