Brake lights- electrical

i have a problem with my brake lights.
i own a 89 camry.. and everytime i step on the brake pedal, the tailights dont come on and neither does the middle brake light...but when i turn on my lights, they come on... but if i step on my brakes then, still nothing
can anyone give me some suggestions or ideas...?
i already changed the bulbs and i once heard it was something to do with the ground wire....??? is that true?

first thing, check the fuse for power and condition.  then move to the brake light switch located on the brake pedal bracket bypass the switch with and jumper wire or a paper clip...

thanks... the fuses have all been replaced and now im gonna do what you suggested