Can 3D Printers be used to print PCBs?

CrossRoads:
The PWB process allowed the wires to be stacked up, crossed over, etc. Didn't have layers of cards.
As I said tho, its been surpassed by gluing multilayer cards together.

...or has it...?

http://www.panasonic.com/industrial/electronic-components/printed-wiring-boards-devices/boards.aspx

Well, maybe that's not the same thing, but on the wikipedia page for "printed circuit board":

...they mention a (patented) process called "MultiWire" which sounds close to what the OP desires (in a certain manner), which was (per the article) still available from Hitachi as of 2010 - I found this:

http://www.hitachi-chemical.com/products_pwb_05.htm

So maybe it is still possible to get...?

Other than the patented process, I wonder how difficult it would be to homebrew a machine to do something like this (probably not easy, certainly)...

/loved the old "cordwood" PCB fab method shown on that wikipedia page...