There were more than this that are active but I didn't bookmark them they were on /r/DonaldTrump that is gone now. They are all still being litigated. The first one had a deadline for writ of certiorari filings today.

Donald J. Trump for President v. Boockvar et al. https://www.supremecourt.gov/search.aspx?filename=/docket/docketfiles/html/public/20-845.html

Joseph B. Scarnati, III, et al., Petitioners v. Pennsylvania Democratic Party, et al. https://www.supremecourt.gov/search.aspx?filename=/docket/docketfiles/html/public/20-574.html

Republican Party of Pennsylvania, Petitioner v. Kathy Boockvar, Secretary of Pennsylvania, et al. https://www.supremecourt.gov/search.aspx?filename=/docket/docketfiles/html/public/20-542.html

Wikipedia is full of twisted fake reportings but here's a list from there: https://en.wikipedia.org/wiki/Post-election_lawsuits_related_to_the_2020_United_States_presidential_election