Brake light pedal switch sticking on.

There is a switch that engages with the brake pedal, check that the pedal return spring is not broken, or the switch mounting is not bent or loose and the pedal comes back and closes the switch.

At the risk of saying FSM, the book is free.
and the steps are clear as day, and is linked here.
if you want me to paste the words from a free book then ok, I guess we can do that."spoon fed sure"
possibles, switch bad, or not adjusted per book.
sorry had to say book. very sorry.
i know folks here hate books...
in the military we say, read the book yet?,
"RTMF?"
then hand it to the guy and point to brake chapter.
Please read it and ask questions we say.

so here it is,
the switch ,also has a jam nut and is calibrated, adjusted when installed. the FSM is free, and online and shows how to adjust it. here, ill post the link and page so you can see all steps.
it is common on this car for the nut to come loose and switch stick closed.
chapter 5 page 16 covers this 100%
no need to guess. at all.
URL:
http://www.acksfaq.com/96-FSM-v1-5-pdf.htm

to test the switch for bad.
key on.
remove switch. still wired per figure 13, id 509
if the switch center pin extends fully
and the lamps still glow the switch is for sure bad. (stuck closed or shorted it is...)

and if the pedal is not damaged or spring
this adjustment works, if not, not.
as they say first things, first.
it's just a pedal and 2 springs.
1 on pedal spring
and one inside the switch, must work.
all first things, that must work.

here is the switch with a real photo.
frame 14(clear photos or group restores them, many)

http://www.fixkick.com/tranny/clutch/mikes-clutch91/shrunk/html/image_14.html

the clutch switch left and brake right.above,
another test is to unplug the switch
if the lamps go out, BINGO, switch bad or not adjusted right.

Recap:
pedal not broken, sticking or jammed in any way or bent.
spring on pedal not broken?
pedal returns 100% to up position?
pedal pushes the switch plunger down.?
switch unplugged, lamp goes out.
it is just a simple switch, no magic electronics.
the switch must be calibrated per the page above.
besides the switch this is pure mechanics.
a lever. (pedaL) springs and a simple switch.