LEDs to Signal Activity

I'm fairly new to circuitry and playing around with a project. Its a three parter but all parts are similar. I want to add LEDs to let me know when certain things are active. I have a Microphone module, a Wireless Module, and Specific Pin that transfers Data that I want to track.

What I'm wondering would be, given a simple microphone on a wire that connects into a circuit board, how hard would it be to add a LED to note when it is powered and ready to receive voice data.
I have a LED with Resistor that function well, with minimal power. But I'm not sure how to approach this.

An electret mic uses a DC current of only 0.5mA. But an LED is very dim with only 0.5mA so a DC amplifier (a transistor) is needed to light the LED when the mic is powered.
Maybe whatever turns on the power for the mic can also light the LED.

you mean the specific pin transfers data digitally? and you want to know when its active?
if thats the case, you can use a diode & a capacitor to rectify the out put and then feed it to a transsitor that would turn on the LED.