How to make your own Contact Mic (no solder) - YouTube
Building (or Buying) Contact Mics – Zach Poff
Replacement DIY for SM16A1 MIC microphone speaker cable 10pins for Hytera HYT MD780 MD780G MT680 etc car radio - AliExpress Cellphones & Telecommunications
DIY Contact Mic - Collin's Lab - YouTube
Make this DIY Contact MIC Circuit | Homemade Circuit Projects