The whitenoise procedural texture generates random greyscale noise every frame. The effect is similar to static on your television.
ATD1 type = whitenoise width = integer height = integer
The whitenoise algorithm fills a greyscale 8-bit texture with random bits. If requested, a color version of this can be implemented as well. Note that this texture will probably not tile very well. In addition, if you have multiple occurences of this texture in the same room, they will all display exactly the same static at exactly the same time. You can get around this by using different offsets and scale factors in the texture to make each one look a little different. This is better than making separate texture definition files, unless you are using very small texture sizes.
type = whitenoise width = 64 height = 64
Will generate a texture like this: