Trying to create a building ghost material, not sure how it's achieved

I’m trying to create a “ghost” placement mode material for a building game I’m making, but I’m pretty new to materials and haven’t found anything online that achieves the effect I want. The closest I found was Unreal 4 Tutorial: Advanced tron material #1 - YouTube but that doesn’t work quite right, especially for complex geometry.

Here is the effect I’m trying to achieve:

Any help would be greatly appreciated!