chrome ignition box: high voltage at the outside?

Ditto above. When you switch off any coil (primary or secondary side), you get a high-voltage kick that either jumps a gap (spark plug), gets dissipated in a diode (often integral with the switching transistor) or bounces back & forth in the capacitance of the wiring. Most switching transistors I have used (MOSFET or IGBT) have clamping voltages between 30 and 1000 V. Automotive ones are usually on the low side. I remember a story of a preacher outside Atlanta who caused a fuss because he shocked kids sitting on his "stool of truth" when they answered bible questions wrong. He claimed it was just a tickle because he used a 6 V lantern battery. He didn't mention the big coil in the circuit.