Normal Mode Continued
Use a voltmeter to check for normal mode problems by putting one lead into the upper left of a wall outlet socket (neutral), and the other lead into the top right opening in the socket (hot lead).
The voltmeter should read approximately 110 volts in the US.
Make sure you keep your hands away from the metal leads of the voltmeter when testing for normal mode problems.
Normal mode situations do not usually constitute a problem.
AC line filters and power supplies usually handle normal mode problems.