You will find information on how to obtain a Swiss criminal records extract on the website of the Federal Office of Justice (FOJ).
If a paper copy of your criminal records extract is to be submitted to a foreign authority it will normally have to be legalised (apostille) by the Federal Chancellery. Do not forget to ask for this to be done at the same time as you order the extract so that it can be taken care of directly through the intermediary of the Federal Office of Justice (FOJ). Otherwise you will have to take the necessary steps yourself with the Federal Chancellery.
A criminal records extract legalised by the Federal Chancellery can if necessary be legalised either by the foreign representation (embassy or consulate) in Switzerland of the country to which it is to be submitted or by a Swiss representation in the country in question. A fee must be paid for legalisation. For additional information please consult the relevant authorities.