const byte fogButton = 7;
const byte fogLamp = 8;

# define ON HIGH
# define OFF LOW
# define PRESST LOW

boolean fogButtonCurrent;
boolean fogButtonPrevious;

boolean fogState;

unsigned long fogTimer;
unsigned long debounce = 200;

void setup() {
  pinMode(fogButton, INPUT_PULLUP);
  pinMode(fogLamp, OUTPUT);
}

void loop() {
  unsigned long now;

  fogButtonCurrent = digitalRead(fogButton) == PRESST;
  
  if (fogButtonCurrent && !fogButtonPrevious && millis() - fogTimer > debounce) {
    fogState = !fogState;
    fogTimer = millis();
  }
 
  fogButtonPrevious = fogButtonCurrent;
  
  digitalWrite(fogLamp, fogState ? ON : OFF);
}