#define SW ?
#define LED ?
void setup() {
  Serial.begin(9600);
  pinMode(SW, ?);
  pinMode(LED, ?);
}
void loop() {
  if (digitalRead(?) == 0)
  {
    digitalWrite(LED, ?);
    Serial.print("OFF");
    delay(1000);
  }
  else
  {
    digitalWrite(LED, ?);
    Serial.print("ON");
    delay(1000);
  }
}