Need help identifying a capacitor
I added your image.

Appears to be a MOV (Metal Oxide Varistor), whose job is to absorb voltage spikes and surges, which it appears to have done heroically.

You can find a whole family of similar devices here - you can choose parameters from the tables to limit the range of types of device, voltages, energy etc.

You'll find that these  look suspiciously similar. From $US0.28 in ones for here.
These are examples only. Many more.


Voltage rating wanted depends on whether your system is 110 VAC or 230 VAC or other. 

Typical specification table below. You care mainly about continuous AC voltage rating and peak current and/or energy handling. Peak current ratings and Joule energy handling should be as large as you want to afford.