The door sensor is a type of switch called a reed switch. It consists of a wired switch and a separate magnet. When the magnet is within about 1/2" of the sensor, the internal switch mechanism is pulled open. When the magnet is further away the switch closes.
Wire the Sensor
If your door sensor has a pair of bare wires, you'll need to join it to a JST-PH 3-pin cable.
Plug each wire of the door switch into the wire joint connector as shown. It doesn't matter which door switch wire is in which side.
Then, plug the black (ground) and white (signal) wires into the other side of the joint connector as shown. You can leave the red wire alone or snip it off, it won't be needed. If you leave it connected, you can secured it to the wiring with a knot to avoid accidental shorts.
Plug the STEMMA connector into the A1 port of the Funhouse.
Mount the Funhouse
Use the 3mm screw inserts and brackets to mount the Funhouse on the wall near the door, close enough for the door sensor wiring.
Mount the Sensor and Magnet
Use the included screws or double-stick foam tape to mount the sensor on the door frame and the magnet to the door.
Plug the USB power into a wall outlet and power up the Funhouse.
Now, when the door is opened, you'll get an alert!