Please help!

[nato]

Can somebody help me?

[Albacore]

Sorry I can't really follow what you're trying to do, maybe because my brain doesn't work well on Sunday's. I see from the attachment that you use the Pen Tool to make a line or shape? If it was a line do an Expand from the Object menu with the Stroke box ticked. You have now changed your line to a shape. You can apply a Zig Zag line around the whole shape. If you just want the effect on one side then you will need to cut the shape (Scissor Tool) and apply filter to that cut line. If I am halfway there could you please come back and I will explain the rest to you as I don't want to go any further if I am barking up the wrong tree!