RV-3 Pilot reported an engine failure while descending into the destination airport. After attempting to restart the engine without success; the pilot was able to glide the aircraft into the airport for a safe landing. Upon inspection it was discovered a grounding wire had come loose and shorted against the ignition switch.

Narrative

While descending into ZZZ from ZZZ1; I experienced light to moderate turbulence (nothing uncommon) while descending into ZZZ; I was a little high so I called ZZZ2 to request a descent through their airspace into ZZZ. Shortly after I checked in; my engine quit. I immediately ran a checklist ABC; airspeed pitched to 90 KIAS; then had to quickly decide where to land; I decided to continue towards ZZZ; I then ran some checks; first I checked mixture (full in) secondary fuel pump on; no change; then i checked throttle; no change; then i switched full tanks (left side had approximately 6 gallons) to right side (approximately 8 gallons;) no change. I then checked ignition; with no change. I then immediately requested priority handling with zzz2 approach. I told them I had a total engine failure and would attempt to glide to ZZZ. I was approximately 5-6 miles out at approx 6;500 feet MSL. I was able to safely glide to ZZZ and was assisted by ground personnel. No damage to myself; aircraft or personal property. The home base for the aircraft is ZZZ; so aircraft was towed back to hangar and the culprit to the engine out was quickly identified. A ground came loose and landed itself onto the Ignition Switch (where both Left and Right Ignitions attach) which caused both ignition systems to ground and in turn shutoff ignition to engine during flight. Approximately 2 weeks prior to this incident the radio (which sits above the ignition switch on the panel) was worked on and the shielding to the wire harness was rewired. I believe it was this work that inadvertently caused the ground wire to become loose and ultimately land itself on the ignition switch and cause it to ground and shutoff both ignitions simultaneously.