Yeah sure youtube whatever you want. The monsters use a bullet movement which doesn't respond to solids, instead, you can use an event like this:
Monster collides with Wall: set Monster angle to Monster.Angle + 180
This just means whenever a ghost touches the wall, it will flip round to the other direction.
I don't think kickit.cap comes with Construct so I can't remember how it does collisions, but there are lots of different ways of making collisions work. You can use the Physics movement, events like above to handle collisions, the Solid attribute, etc.