The clock runs off of 120v. And again that shouldn't happen. If you connect 120 to the stove, then run the same connection off of a leg to the oven, it shouldn't come on based on the stove's activity. I'd still check the polarity, but that's just me and I borrow trouble all the time.The oven wasn’t turning on, the clock and display were lighting up. I think when I turned the cooktop on, 120 volts was backfeeding to the oven display thru the common 220 volt connection.
If that stove or oven ever shocks you though, it could be a hum dinger!