It goes without saying…but whenever you download and use any code or script from this site, or any site for that matter, you should review and understand what the code or script is doing before you attempt to use it.
Using the PowerShell scripts that I share as an example. I distribute these scripts as text files as it provides an opportunity to review the script, after which you can knowingly rename the file. This also prevents any hastily or accidental execution of the script.
And as with anything you download from the internet – you should test it in a dedicated environment prior to any production environment.