You could link an object to the avatar and change it's emissive property to simulate a blinking light:
Code:
import viz
import vizact
import vizshape
viz.go()
ball = vizshape.addSphere(radius=.03,pos=[0,1.8,4])
ToggleLight = vizact.sequence( [vizact.waittime(0.3), vizact.method.emissive(viz.YELLOW), vizact.waittime(0.3), vizact.method.emissive([0,0,0])], viz.FOREVER)
ball.runAction(ToggleLight)
avatar = viz.addAvatar('vcc_male2.cfg',pos=[0,0,5],euler=[180,0,0])
headbone = avatar.getbone('Bip01 Head')
link= viz.link( headbone, ball)
link.preTrans([0,0.3,0])
avatar.runAction(vizact.walkTo([-5,0,30]))