Thanks, just so I am clear if this mistake was noticed before hitting the next shot 20.6 would apply and if it was after 20.7 would
20-6. Lifting Ball Incorrectly Substituted, Dropped Or Placed
A ball incorrectly substituted, dropped or placed in a wrong place or otherwise not in accordance with the Rules but not played may be lifted, without penalty, and the player must then proceed correctly.
20-7. Playing From Wrong Place
c. Stroke Play
If a competitor makes a stroke from a wrong place, he incurs a penalty of two strokes under the applicable Rule. He must play out the hole with the ball played from the wrong place, without correcting his error, provided he has not committed a serious breach (see Note 1).
If a competitor becomes aware that he has played from a wrong place and believes that he may have committed a serious breach, he must, before making a stroke on the next teeing ground, play out the hole with a second ball played in accordance with the Rules. If the hole being played is the last hole of the round, he must declare, before leaving the putting green, that he will play out the hole with a second ball played in accordance with the Rules.
If the competitor has played a second ball, he must report the facts to theCommittee before returning his score card; if he fails to do so, he is disqualified. The Committee must determine whether the competitor has committed a serious breach of the applicable Rule. If he has, the score with the second ball counts and the competitor must add two penalty strokes to his score with that ball. If the competitor has committed a serious breach and has failed to correct it as outlined above, he is disqualified.