2001 Maxima w/ Stop Light Switch Issues

[2001I30MAX]

The brake lights on my Maxima didn't work and also unable to shift gears(A/T) so I changed the stop light switch with a new one. It worked for a day or two and then it started the same problem again. I put the old, original switch back and it worked for a day or two and stopped working. I tried again with the new switch and I am getting the same result.
Does anyone have any idea as to what might be the cause of this or experienced a similar issues? I checked fuses and relays and they all seem to be fine.
Thanks in advance for your comments/input.

[Ace2cool]

Surely the wires aren't bad? Are you sure the switch is properly adjusted? Do you have access to a multimeter?

If not, try wiggling the wires down there as you press the pedal and see if anything changes.

[2001I30MAX]

With a multimeter, what or how do I check for? I am gonna get one for future use, as well.
Thanks

[Fezzik]

You can always try wiggling the wires when its not working and see if that causes it to work. Try the connectors too. Any corrosion in the area