christmas light controller

Hi all, I am think about making sum Christmas light and am looking for info on how to make a strand of lights flash between to different sections where one its one while the other is off and vice basicly the effect of legs running our dump truck bed dumping. Would like to have one that goes in the stand of lights not a separate unit. Thanks for any help

did you goggle it?
There must be a lot of controllers that can do that.

I have been looking but not real familiar with controllers to know what I'm actually looking for is there some kind of relay our something I can find at radioshack to wire in. Thanks

Like this;
https://www.thechristmaslightemporium.com/product.asp?itemid=2544&gclid=CJ3mwNC0n7YCFQ9nOgodG3AA2Q

or this;
**broken link removed**