buzzing sound

i turn on my jeep and i hear the buzz from the fuel pump then after that theres a costant high pitch buzz (sounds like a light post at night)

has anyone have had anything similar or maybe something is vibrating ?

cas

I've got an odd buzz but only when accelerating. It doesn't sound electrical either

just last week i had the same sound but only after i turned off the engine? wierd. I did not occur again