int SwitchPin = 8; 
int Switch = 0;
int led_blue = 13;

void setup() {
  pinMode(Switch, INPUT);
  pinMode(led_blue, OUTPUT);

}

void loop() {

  Switch = digitalRead(SwitchPin);
  
  if(Switch == HIGH){
    digitalWrite(led_blue, HIGH);
  }
  else
  {
    digitalWrite(led_blue, LOW);
  }
}