Electrical trap doesn’t have to be sophisticated, two wires, a grill of conductive metal, maybe two copper pipes and a car or bike battery. I’m not expert in the field of electricity but I believe a car battery can deliver a substantial amperage thus might be lethal. So assuming that zombies react to electric damage per analogy of human organism, and also assuming the zombie has no non conducting clothes or armor, such trap, in which zombie closes the circuit, would result in two scenarios: either a damaging shock, or if resulting paralysis keeps the body locking the circuit the current would flow untill battery either fails or empties, potentially killing the victim. Not burning as suggested. Zombies act on instinct so any trap obvious to the eye of a human would be ignored by them, making them more effective.
Also on that principle one does not need a bouncing mine. Just hang the mine on a stick in the air, and attach some wires to the detonator.
Shaped charges would be great as alternative door breaching methods.