Television Actors reappearing in a show in a different, unconnected role

[RedC]

It's happened a few times in It's Always Sunny.

 

[Minkaro]

Sean Gunn appears in two completely different roles in Angel season 1.

The first time he’s a demon, so under lots of makeup.

 

[Cole9]

'Knowing Me, Knowing You with Alan Partridge' is another one that has several actors playing different roles, e.g. David Schneider, Rebecca Front.

 

[Amir]

I didn't think they do it nowadays. Knight Rider in the eighties had tons of actors reappearing in different guest roles. Even actors who appeared in major guest roles in the most memorable episodes then returned in a different role. I found it strange. Surely there were enough actors around!