Flash MX 2004.
stroke.waveLength
Property; a string that specifies the wavelength of a ragged line. This property is available only if the stroke.style property is set to ragged (see stroke.style). Acceptable values are "very short", "short", "medium", and "long".
The following example sets the waveLength property to short for a stroke style of ragged:
var myStroke = fl.getDocumentDOM().getCustomStroke();
myStroke.style = "ragged";
myStroke.pattern = "random";
myStroke.waveHeight ="flat";
myStroke.waveLength = "short";
fl.getDocumentDOM().setCustomStroke(myStroke);