Create a mask from a shape layer

[lessdauphins]

Is it possible to take the paths I have on a shape layer and move them into the mask path of a different layer?

[Mylenium]

Copy & paste. I suggest you read the online help on such basics.

Mylenium

[lessdauphins]

Funnily enough, I tried copy and paste. The result was that it copied the key frames and not the paths.

[Roland Kahlenberg]

What did you select, to copy and where did you paste it?
You should select the Shape Path property and paste it into a Mask Path property. HTH 

[Meng Zhiqun · Accepted solution]

If it's a path drawn by pen tool, go to the shape # > path # > path, select and copy it. Select the layer that you want to paste to, try selectig the pen tool and click once on the viewport, as if drawing a mask. With that single point drawn, now paste the shape. It should appear as a mask now.