Thank you Ray. I just tested it by hooking up a multimeter to the nodemcu, and it stays at 0v (even when I reboot it). The volts only go up when I switch the door open/closed.
I will order a relay that activates on high. Thanks for your help.
Thanks for your quick reply. So the signal is actually low coming off the board during boot, right? In that case, I will order a relay that is active on high, and test again.
What is the best way of testing with a multimeter if it is high or low?