It was fairly commonplace for TGIF sitcoms to cross over — remember when Steve Urkel paid the Tanner family a visit? — but Sabrina took place in a supernatural world, whereas "Boy Meets World" (mostly) took place in our reality.

Even weirder than Eric going out on a date with the titular Teenage Witch was having Salem show up the following week and transport Cory, Topanga & Co. back to the 1940s for a World War II-era adventure.

Boy Meets World Season 5, Episode 5 and Episode 6

https://tvline.com/lists/weirdest-tv-crossovers-list-video-supernatural-bones/boy-meets-world-sabrina-the-teenage-witch/