turn signal shortage

There seems to be a short in one of the filaments in my right turn signal, but it still occurs after switching the bulb. Sometimes, if I turn the signal to go right, it will blink as brightly and at the normal speed as usual. However, intermittently it will begin blinking fast, and one of the filaments will be out. When it does this, the front turn signal will only have one working filament, will be blinking fast, and will be significantly dimmer than normal. It's just a little annoying, but I'm more concerned about getting pulled over for having an out signal when in reality it's just a short in a filament...