My trunk randomly opens either whil parked or while driving how do I keep it from doing this and I disable the switch, and if so where would the switch be in a 1992 RX-7 FD3S

 

If you have an FD, the hatch was known to get out of adjustment over time causing an annoying rattle. There is adjustment on the lower mechanism for the hatch. If I had to guess, someone adjusted yours too low in an effort to stop the noise and now it's not latching completely. IIRC, a couple of 10mm bolts. Loosen and move the latch assembly up a millimeter or so at a time. You don't want it to be too loose or the rattle problem might return.
There is no switch. Just the release lever next to the driver's seat on the floor.