Backup lights and turn signals

I have an intermittent problem that when I place the transmission in reverse, my left turn signal lights turn on. When I place my turn signal light on to turn left, the backup lights also flash. Any thoughts on what the problem may be? Thanks for your comments.

Well it may be that the piece of metal BMW uses to ground and power their lights without all the wires might be broke in the left side cause a circuit prob. giving power where it don't need to be or it may be burned.some i've seen get rusty from condensation and brake or don't contact good if this is the prob u might can solder and fix it or buy a new one.Hope this helps.