Dashboard indicator lights 2000 chev Venture

2000 Chevy venture 110,000 miles
I have notice of late when I apply my brakes that the turns signal indicatators light up simulataneaously and stay on as long as the brake is appplied. Also when I apply the brakes with the left turn signal activated the speed of the turn signal increases until I release the brak again and it then goes back to the normal flicker speed.

Any ideas as to what is causing this and how I would likely solve this situation.