old_contents: #!/usr/bin/env python3
  """
  Class to handle one of the front boxControls (LIGHT, VENT, HEAT)
  sets up the GPIO interrupt
  handles the interrupt
  
  """
  
  import RPi.GPIO as GPIO
  
  class boxSwitch:
      """ Class to handle one of the front boxControls (LIGHT, VENT, HEAT) """
  
      mySwitch = None # pin assignment for this switch from RPi GPIO
  
      def __init__(self,GPIOpin):
          self.mySwitch = GPIOpin
          GPIO.setmode(GPIO.BOARD)
          GPIO.setup(self.mySwitch, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
  
      def get_STATE(self):
          return GPIO.input(self.mySwitch)
  
      def setCallback(self,callbackFunction):
          # Define a threaded callback function to run in another thread when events are detected
          GPIO.add_event_detect(self.mySwitch, GPIO.BOTH, callback=callbackFunction)
  
new_contents: #!/usr/bin/env python3
  """
  Class to handle one of the front boxControls (LIGHT, VENT, HEAT)
  sets up the GPIO interrupt
  handles the interrupt
  
  # boxControls variables
  # GPIO pins assigned to the two front-panel switches
  boxVENT = 12
  boxLIGHT = 16
  boxHEAT = 10
  
  """
  
  import RPi.GPIO as GPIO
  
  class boxSwitch:
      """ Class to handle one of the front boxControls (LIGHT, VENT, HEAT) """
  
      mySwitch = None # pin assignment for this switch from RPi GPIO
  
      def __init__(self,GPIOpin):
          self.mySwitch = GPIOpin
          GPIO.setmode(GPIO.BOARD)
          GPIO.setup(self.mySwitch, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
  
      def get_state(self):
          return GPIO.input(self.mySwitch)
  
      def set_callback(self,callbackFunction):
          # Define a threaded callback function to run in another thread when events are detected
          # event_detect returns the GPIO pin that has changed
          #   so the function should look like:
          #   def callback(GPIO_pin_changed):
          #      print("The pin that changed is ",GPIO_pin_changed)
          GPIO.add_event_detect(self.mySwitch, GPIO.BOTH, callback=callbackFunction)
  
subject: clean up function names, improve docs