I had similar with headphones wrapped around an old battery-powered mechanical alarm clock. Wires, timing mechanism, cylinders of dense material... that got stared at quite hard before a muttered comment of "Don't pack like that again" and I was sent on my way.

I recommend packing any cables or loose electronic widget accessories in a small bag and pulling it out seperately for screening. Amenity kit bags are good for this, so are the smallest luggage organiser bags. I put all my laptop charger, cables, connectors, adapters, etc, etc into a separate bag and since I started to take it out, my rate of secondary search has fallen to almost zero.