Below is a good evangelistic idea by Intervarsity Christian Fellowship. Below are the links I found. If these links don't work, type Intervarsity Christian Fellowship Red Cup Campaign in your favorite search engine such as www.google.com or try and find it on the Intervarsity Christian Fellowship website.
Below are the websites about the Red Cup Campaign.
https://2100.intervarsity.org/overview/thirsty-campaign
http://www.intervarsity.org/news/red-cups-new-role-campus
https://2100.intervarsity.org/resource-keyword/red-cup
https://2100.intervarsity.org/resources/ppt-background-red-cup-proxe
https://www.mnnonline.org/news/red-cup-campaign-instigates-thousands-of-gospel-conversations/
http://2100.intervarsity.org/overview/thirsty-campaign
https://intervarsity.org/news/red-cup-campaign
Below are the youtube ande vimeo videos about the red cup campaign.
https://www.youtube.com/watch?v=cU0hFYP1G1E
https://www.youtube.com/watch?v=D3QLTqcha4A
https://www.youtube.com/watch?v=D3QLTqcha4A&t=75s
