No person offered as a witness in any civil action, suit or proceeding shall be excluded by reason of his interest in the event of the action, suit or proceeding, or because he is a party thereto, except as follows: No party to any action, suit or proceeding, nor any person interested in the event thereof, nor any person from, through or under whom any such party or interested person derives any interest or title by assignment or otherwise, shall be examined as a witness in regard to any personal transaction or communication between such witness and a person at the time of such examination, deceased, insane or lunatic, against the executor, administrator, heir at law, next of kin, assignee, legatee, devisee or survivor of such person, or the assignee or committee of such insane person or lunatic. But this prohibition shall not extend to any transaction or communication as to which any such executor, administrator, heir at law, next of kin, assignee, legatee, devisee, survivor or committee shall be examined on his own behalf, nor as to which the testimony of such deceased person or lunatic shall be given in evidence: Provided, however, That where an action is brought for causing the death of any person by any wrongful act, neglect or default under article seven, chapter fifty-five of this code, the person sued, or the servant, agent or employee of any firm or corporation sued, shall have the right to give evidence in any case in which he or it is sued, but he may not give evidence of any conversation with the deceased.