I took apart a microwave recently and found out it could not be repaired. That's just how it goes sometimes.
But,,,, I did see a big Capacitor inside of it !! Capacitors have the ability yo hold a lot of power and deliver it on one big jolt !!
If you don't know your way around the inside of devices like this then I would recommend you don't try. No use hurting yourself over a fairly cheap applaiance.
The ambulance ride would cost you a heck of a lot more then a new microwave.
( I don't know if it would kill you but, it would shock the heck out of you. And of you are older it would be bad for your hart and stuff. )