That may be normal leakage from the Y capacitor between the primary and secondary. 250 microamps of leakage (IEC 60950?) is allowed, which you can feel but is h

That may be normal leakage from the Y capacitor between the primary and secondary. 250 microamps of leakage (IEC 60950?) is allowed, which you can feel but is harmless. I am told that the Y capacitor reduces EMI (electromagnetic interference).