I had a similar issue with a 96 Continental I used to have. It turned out to be a speed sensor on the rear going bad. Being cheap, I just went to the salvage yard and got a couple and replaced both rear sensors. The light went off within a day or so, and I never had another issue with it.
I am currently having an intermittent ABS light issue on my 91 Explorer. I have had a lot of problems with this one, between the ABS module and the rear brakes themselves. I'm considering bypassing the rear ABS altogether (The 91 has rear ABS only). I actually ran across your post while looking for some insight into this project.
In short, if you have not had your brake system open and have not had any issues with air in the system before now, I would suggest focusing on the speed sensors first. If your ABS module turns out to be bad, it's easy to change, but a pain to bleed it as it requires a special tool to plug into it and cycle the module to bleed it.
Good Luck!
Ken
crazy thing... my abs light came on today for the first time. just before it came on i felt a slight drop and what felt like air in the system. i looked into it put reader on and got nothing... but light was still on? about 4 hrs later i went to local conv store and light was off??? weird anyone have an answer to this?
