We sell gear to find these kinds of issues. The best story so far, was a little old lady with an ancient table-side lamp, which had a faulty connection, which w

We sell gear to find these kinds of issues. The best story so far, was a little old lady with an ancient table-side lamp, which had a faulty connection, which would sometimes arc, with just the right shape of wire attached to it to broadcast noise all over the GSM bands. Now GSM is (from the perspective of the phone's broadcasts), pretty weak, so that enough to periodically wipe out cell service for a couple of neighbourhood blocks.