Various lighting problems with 93 Olds Supreme

The signal lights don't really work. If you can get the flasher switch in just the right spot, then they'll go. For example, if you're turning right, you've got to apply pressure to the switch to push it all the way up. If you're turning left, then you've got to get it just a smidge below the midway point.

Also, one of the rear brake lights doesn't work. I've replaced the bulb to no avail. Ideas?

for that brake light, check if you have power going to the connector, have a friend push the break pedal while you sit there with a meter to check for voltage, or try and put some contact grease in there, so that the contacts touch the light bulb, that could be the problem. also you probably have a short or some kind of problem in your steering column, my brothers car has the same problem, his horn kept going off so we had to pull the fuse, and sometimes he says smoke comes out from the steering wheel, i dont know if you have those problems, but keep an eye out.