This easy-to-use fire alarm works by detecting flames in the surrounding area. It utilizes very simple electronic components and comes in 3 main parts that are easy to print without supports. 

I printed this project on my trusted Ender 3 Pro with no problem.

Here is a parts list for what I used:

• 5mm LED x 5
• Toggle switch MTS-101 x 2
• Mini Breadboard
• BC547 Transistor
• 4AA battery holder
• AA batteries x 4
• M3x12 Screws x 4
• Flame sensor module (3 or 4 pin)

A simple circuit diagram is attached above.

Total print time: 6 hours

UPDATE! I will be posting a few photos soon of how the final product looks like !