We are going to make an animation that looks like this:

Part 1: Photoshop

1. Open up a new document with a transparent background and make it the size you desire.

2. Create 4 layers and using the Paint Bucket Tool change the background of all the layers to black.

3. Click on Layer 1 and go to Filter >> Noise >> Add Noise and use the following settings:



4. Repeat step 3 but use these Amount for other other three layers.

Layer 2: 85
Layer 3: 95
Layer 4: 105

5. Now you Layers window should like like this:


I just changed the name of the layers in order to let you know that you should have Amount: XX on each layer.

6. Now jump to ImageReady.

Part 2: ImageReady

1. Ok now hide all the layers in your Layers Window except for Layer 1(75):



2. Duplicate the first frame in the Animation window. Now hide all the layers in your Layers Window except of the Layer 2 (85).

3. Repeat step two but with Layer 3 (95) and Layer 4 (105).



Final Product