Some  of the common scams listed here, on 800notes, are  the "you won a prize" or "free grant" or "award" scams.
Those scams are described here:
http://phonehelp.2truth.com/facts.html

(That site also has a link to Amazon's phone blocker devices and apps, as well as a page showing various government sites that accept complaints or warn about scams.)

How I have won a prize and wanted me to call a phone number to see about it.