Does not sound good,
does it give you a error code at all?
the flashes of light sound like a heating element problem, and as far as it turning on itself thats a control issue, I would leave it unplugged for safety reasons.
I am trying to see if I can find some information online about this particular oven.
I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_54ae41aaaffbab00