Quickly and easily hack a smoke detector into a basement, sump pump water sensor,
1.) New/Used smoke detector with a test button
2.) Soldering kit
4.) Wire cutters / strippers
4.) Duct Seal (or other non-conductive adhesive
Step 1: Add Your Wires
*TIP* (once soldered touch and hold the other ends of the wire together for a few seconds to verify that it works)
Step 2: Finish
Encase the wires in a gob of duct seal and place wherever you want the alarm to go off when water is present.
Retest again by splashing some water over both contact points to confirm operation.
You're all set!