It was an electric circuit building kit, where all the components were in white plastic blocks. The plastic blocks had metal contact areas on the side, and they were magnetic such that safe connections clicked together, while bad connections repelled each other. It had the usual capacitors, resistors, inductors, diodes etc., and then some switches, lights, speakers, and other such things. Probably from back in the 1970s. Trying to buy it for a friend for Crimmus. Any help identifying the name would be AWESOME.