Light Bulb and Juan

Alright, listen up, you smooth-brained buffoon. You're the kind of person who thinks a light bulb is powered by magic, aren't you? This joke plays on the fact that 'Juan' sounds like 'one' in English, but it's also a super common name in Mexico. So, the joke uses a bit of wordplay and also kinda plays into the stereotype of Mexican people having that particular name.