Random Blinking LEDs, Control Speed

My school play needs a prop made, I have basic circuitry skills, can solder, understand most schematics, etc. There is a part in the play where the actor will open a box and LEDs will begin to blink randomly to make a magic effect. I think I am looking for more of a fade in/out effect than blinking. I also want to have a knob that will control how fast the LEDs will fade. Can someone please help me out with how I would go about doing this. I have a PIC programmer if I need to use a PIC, also willing to purchase an arduino UNO if needed.


Thanks for all help in advance.

Hi. Just a quick thaught throw out in the air:

Use two square wave oscillators. Make one of them voltage controlled (VCO, schmitt trigger oscillator with adjustable trig level for schmitt trigger) and make the output be a function of logic AND for the oscillators output.
Make the voltage that control the VCO coming from a a LED (can be used to measure light).

This way, the random changes of ambient (or spot, depending on the LED's design) light will cause output being random.

There is a lot ow ways to do this. I just had a very simple idea to start with.