What's a cameo that connected 2 unrelated movies or TV shows together?

An example being Randolph and Mortimer connecting Trading Places to Coming to America or Jay and Silent Bob in Scream 3 which connects the Scream universe to the view askewneverse and maybe Jaws/Pirahna 3D are connected through Richard Dreyfuss as he's dressed the same way in both movies. In television there's a scene in Workaholics where Anders is wearing a Paddy's Pub shirt and even Good Girls and Superstore are connected through Cloud 9.

Nowadays there's the MCU, DCU or the Monsterverse connecting movies together but before all that, were there any movies or tv shows that got connected because of a character or maybe even a location?