An advertiser targeting only France determines that clicks have been received from people in Switzerland. Why might this happen?
Swiss people are searching on Google for information about Switzerland
People located in Switzerland are searching using France-related words, like “hotels in Paris”
French people visiting Switzerland are searching on Google for information about Switzerland
People located in France are using Swiss-related words like “hotels in Switzerland”
You can help ensure that your ads reach the customers you want. Use location and language settings to have your ads appear to customers in your targeted geographic locations, or to customers who have selected your targeted language as their interface language. With your location settings, you can target the geographic areas where your ads can appear. For example, if you own an e-commerce store in the United States and you want to target the state of California, you can use your location settings to do just that.
By default, you’ll be able to reach people who are likely to be physically located in your targeted areas, as well as those who show interest in your targeted geographic areas.
If you restrict people from outside of targeted location, You need to choose “Reach people in your targeted location” in your advance location targeting option.
Read more here: https://support.google.com/adwords/answer/1722038?hl=en