hi there
you could do something like this:

Code:

---

var green = 128; 
var blue = 128; 
var red = 128;

function turn_it_on()
{

if(interruptor_pushed == true)
{
light_bulb.lightrange = 300;
}
else
{
light_bulb.lightrange = 0;
}

while (1) 
{
my.lightgreen = green;
my.lightred = red; 
my.lightblue = blue;
wait (1); 
}

}

action light_bulb
{
light_bulb = me; 
light_bulb.passable = on; 
light_bulb.invisible = on;

turn_it_on();

}

---

you could also increment lightrange step by step to get a dim effect