Where's the lever/golden key on level 4?

[Cadunkus]

I clear up everything everywhere but can't find either the golden key to the door on the far right or the lever to the drawbridge. Not sure which one I need to progress but I can't find either.

[FibS]

On the right-hand path, by the moving fire trap, the alcove has a switch on the wall.

This switch opens the door overhead, which you need to hop off the balcony and take a secret elevator to get to. It has a spike trap in it and the key.

Behind the door is the 2nd golden chest and the drawbridge lever.