You want to create a web page that scans and displays the wifi networks around the user who's browsing your site? That's not possible.
With php, the code runs server-side so you cannot detect the user's wifi networks, only those around the server (assuming it has access to a wifi adapter)
With client-side javascript, that can't be done. Unless you use Node.js, but that runs server-side just like php.
With browserify you could run nodejs stuff on clientside