Hello, To augment Craig Smith's comments on a metal strip near the
tube, application notes on many rapid-start ballasts say the metal
should be grounded.  A ballast on an un-lit tube generates rather high
peak voltages, due to the core design which saturates on part of each
cycle.  Having this spike on the end electrodes near a ground reference
enhances the electrostatic field which initially fires the tube.

Bill Earnest
Allentown, PA, USA