Select the object or group (or target a layer in the Layers panel).
To apply the effect to a specific object attribute, such as a stroke or fill, select the object, and then select the attribute in the Appearance panel.
To apply the effect to a graphic style, select a graphic style in the Graphic Styles panel.
To use a preset scribble effect, choose one from the Settings menu.
To create a custom scribble effect, begin with any preset, and then adjust the Scribble options.