After some research on electric mics I created a simple circuit on breadboard to connect it to an Arduino.
An electric mic has typically 2 pins, the negative rail is always connected to the case which are clearly visible. All you need is to check out the bottom of the mic, and find traces of connections to the case.
I'm not quite too sure about the correct resistor value between 5V and the mic + side. Most schematics use 2K resistors, so I stick to it temporary. I need more research on this.
I also added a small capacitor between mic + side and output which is recommended for removing the voltage source's DC signal. Which reminds me about reading more about DC + low pass filtering.
Connecting output to one of the analog ports and using the Arduino IDE Serial plotting function I was able to see some signal changes using this code: