There are always a lot of '88-'89 headlight switches showing up on eBay and I would be very leery of buying one of them. I have had lots of experience with these switches and buying a used one that has not been fully tested is very risky. Two things go wrong with these switches. The parking lights will not go off when pushing the off switch after the headlights have been on or you have to punch the off button to make them go off. The other problem is the background lights on the headlight switch module, the wiper module and the CRT might not come on when the headlights are turned on.
When I buy these switches I only have about a 10% success rate of getting a good one. When I get one that does not shut off correctly or the background lights do not light I take them apart and spray the contacts inside. I then retest them. If they still do not work correctly I then completely disassemble the module and actually sand and clean the contacts and the try testing again. Sometimes I then have success but most of the time not. I currently have about 25 switches in my cabinet that look great but will not work and at the moment I do not have any good ones available.
I see these switches going on eBay for pretty good money but I am sure very few of them are actually working correctly. I have no interest in killing some eBay sales as I do not have any for sale myself at this time but post this as a warning to switch buyers.
Ask the seller if the switch has been fully tested and these points addressed.