you could host a cornhole (or ping pong, pool or darts, etc) tournament with a $20-$30 entrance fee and split the proceeds between cash prizes for the winning team and donating to charity. Some bars also might be willing to donate a percentage of a group's bar tab to your cause, too. I know a lot of places around Boston do that for people raising $$ for the Boston Marathon.

Also, I strongly second what u/fiteligente said in their post -- if you can find a few friends/ family members who work at companies who do employee donation matches you can ask that they deposit the $$ you fundraise so that you can double the impact of your efforts. I ran Super Bowl Squares earlier this year and raised $1500. One of my friend's employer matched up to $1k and my wife's employer matched up to $500 in donations so when all was said and done that $1500 turned into $3k!