Whirlpool Microwave Cooking when off

My mircowave has a lot of problems.

The most dangerous problem is that when the time ends the light inside goes off and the fan goes off but I hear a humming sound. The microwave is still ‘cooking’. I have let the timer beep for 5+ mins in the past only to open the door to find a mess.

When I open the door and close it or hit cancel the microwave will start humming again and be cooking inside. Eventually I’ll go back later to close the door and 50/50 it starts humming again or it will behave.

Other random symptoms include the microwave will not turn on when I hit start and when it does start the turn table will not spin even though the light is on and no cooking will be done.

It works flawlessly 25% of the time. Did I get a lemon?

The lemon law is effective when you have had the appliance repaired for the same problem three times, and the problem has not been corrected. It sounds to me by your description that you have a bad control board. Unplug it and have a professional technician look at it.