By cleverly patching into the test button on an old smoke detector he created a circuit-trip alarm. One side of each piece of wire is secured to the frame and jam of a window. A paper clip ...

And can I connect a battery-operated unit in my garage to the wired detectors?

When smoke enters this chamber, a few transistors sound the alarm. If you’ve ever taken one apart, you can probably rebuild the circuit from memory. Because these alarms are so simple ...

Head to your electrical panel and shut off the breaker marked with “fire alarm” or something similar. It may be piggy-backed ...