There are a few different WordPress plugins that allow you to set up competitions on your website and take a percentage of the cost, such as RafflePress and WP Contest Creator. These plugins typically allow you to create different types of competitions, such as raffles or giveaways, and set up entry fees for participants.
However, it sounds like you’re looking for a plugin that allows your members to create and run their own competitions on your website, which is a bit more complex. One option could be to use a membership plugin that allows you to create different membership levels, with higher-level members having the ability to create and run their own competitions. You could then take a percentage of the entry fees for each competition.
Some popular membership plugins for WordPress include MemberPress, Restrict Content Pro, and Paid Memberships Pro. You may need to customize the plugin or use additional plugins to achieve the specific functionality you’re looking for, such as the ability for members to create and manage their own competitions.
thats the idea to a tee members run there own raffles and we take precentage ill look at member plugin, I used lottery plugin before to run my own raffles on Woocommerce,
Like I mentioned before, the things you want to achieve is a bit more complex than installing a single plugin.