So about a few days ago my brake lights started to become erratic.
As I was testing the brake light switch, I noticed something weird:
Occasionally the brake light would come on when I engaged the brake pedal, but kept the switch in its disengaged form.
Meaning, it didn't seem like the switch had anything to do with the light coming on, and there was something else was engaging the light.
Would anything else engage the brake lights?
Running lights still work
The brake lights are not working 80% of the time.

 

If your car has/had cruise control - Many have confused the cruise control cutoff switch that touches the brake pedal with the brake light switch that touches the pedal higher up and is much harder to get to. Does the switch you are testing look like this?

 

Interesting! that could be it
Ive attached what the switch looks like that I was referring to
Now the question is, where is the switch located in mid 80s 240s. ive seen posts about 90s models being located in the dash. but you mention it being higher up on the lever. has anybody accessed this from below or does it still require taking the dash apart?

 

The switch with the vacuum line is the cruise control cutoff switch. Has nothing to do with brake lights. Brake light switch is higher up touching the pedal.