is electricity smell from microwave after metal was put in it mean the microwave is ruined?
No. If the microwave still heats, it's not ruined.
Here's a nice video of the aluminum coating of a CD being burned off by a microwave.
Notice the plasma balls rising to the top of the oven. They'll produce ozone, which has an electrical burning sort of smell.
You can get the same plasma balls using a match or candle. That doesn't wreck the microwave either; makes a heck of a scary sound though.
You can also smelt aluminum, or even silver and iron in your home microwave without damaging the device.
If you make a habit of doing things like this, it's best to have a dedicated oven for the job, as melted plastics, heavy metals, and metal oxides do not mix well with food.

Washing out the microwave's insides should take care of any residual smell for you.