Electrical Problems

I drive a 98 Impreza 2.5RS I love it and wouldn't get rid of it for the world. But it seems I have run into an electrical problem and I am in need of some advice. While driving down the road my door locks and interior lights will randomly just flip on and off (or locked and unlocked) also my drivers side headlight sporatically goes out, and it is quite annoying. If anyone has any insight on where I could start here please let me know