Ok I have a 70 Chevelle and the dash lights all work fine, but when i press the brake pedal the dash lights go on, also the turn signals work fine along with the brake lights but when the signals are on the dash lights all flash when the signal does, what could this be?

Bad ground maybe

Do the brake and signal lights work fine on the outside of the car? They could be trying to find ground through the parking light circuit ( which also powers the dash light circuit) Since it happens with both the brakes and signals, the problem is probably in the trunk. Check the bulbs, sockets and the ground in the trunk.