[Morten Orre]

Hi.

Ancient old post, but a simple solution would be:

Choose the layer needed, manually just add a square mask, make sure it sits on the very edges of the frame.
On mask settings, choose “none” just to make sure it does not crop anything.
Now add stroke in effects and choose the mask you just made and play with the settings.

Everything can also be animated.

Best regards
Morten Orre