Not exactly a "Disability PSA" but a film short that makes its point well...

[capri0mni]

I have some quibbles with how the story's told, but, overall, I really liked this. It was posted 5 years ago, when YouTube's time limit was 10 minutes, and this is just a smidge over, so it's posted in two parts:

These versions are interpreted in BSL with English subtitles:

Part 1:

Part 2: