2000 chevy S-10 blazer 2WD

I have an electrical problem:When the vehicle is running the brake lights are on all the time, & the right turn signal does not work but the left side does(front & back outside & inside the car for both). I've replaced the bulbs - that did not help at all. The vehicle can be off & keys removed - but if I step on the brake it has all the instrument lights in the dash & outside lights , radio, etc...... come on light I was getting ready to start the car. On, off, on ,off as I press & lift, press & lift. I have been told it is the brake light switch by some or the turn signal switch by others. I would like to only replace what I need to.......but don't know if it's another problem or one of the 2 switches. brake light switch is much cheaper than the turn signal combo switch(cruise, turn signal, hazards) Thanks in advance thejohnforcefan