One of our Oortian backers had a cool idea for this that I like. These “pipes” are not visible or collidable in the real word so you don’t have to clutter your house with electronics/magic/steam whatever. Instead, users have some sort of e-goggles that they can equip that allow them to see these pipes along with a matrix style transparent world (so you can see the pipes going through the world). In this view you can only select blocks that interact with “pipes” so you can easily place a pipe inside of a wall.
For the actual “electricity” stuff I am a fan of the common logic gate blocks and a CPU mini block that then has a 2D tile GUI with inputs and outputs. Probably something like this http://www.neuroproductions.be/logic-lab/. However, none of this stuff has been thought out or designed properly yet.