tiny lightning

so there i am, heating up my hour-old coffee in the microwave before trotting up to work, when i hear an odd 'buzzing' sound.
it wasn't quite a 'waspy' buzz or a 'someone mowing their lawn down the street' buzz...it was a little off.
while i was mentally investigating this audio mystery my eye picked up some wild flashing in the peripheral feild, which seemed to be coming from my once trusted microwave.
so i flicked off the kitchen light, and sure enough, there was a tiny lightning storm pouring out from the bottom part of the microwave door and onto the counter.
i've seen lightning 'inside' the microwave many times, like when i put CD's in there, but seeing it escape the confines of the appliance is a bit unsettling.
this microwave is only four years old, and i find it bizarre that it suddeny decided to release random bursts of energy.
there must be a breach in the door mechanism.
when i finally opened it there were scorch marks and the distinct smell of burning equipment.
this did not affect the taste of my coffee.