i have neckband blutooth ear phone , its batter is bad , so i modded wires to it with single 18650 battery , may be its contacts are visible outside .
another thing - the on off swtich is broken , so now my blutooth is always kept on which switches itself off when nothing to connect .
before few months back , i use to hang the neckband blueth on the psu plug , when i swtich on in wall switch , the light in bluetooth use to flickr once , i dint mind it , i thought may be some loose connection .
now i keep it at table , and near a extension box for fiber modem adapter is place...