If you are concerned about liability coverage, regular homeowners insurance should provide some coverage you (as long as you do not charge admission). You should read your policy carefully and talk to your agent. Renters insurance typically covers liability also. If you have lots of visitors, you may want to up your liability limits. I have opted for the maximum limits my insurance allows. Additionally, my carrier (State Farm) has an umbrella liability policy that I purchased separately from my homeowners. That policy extends my liability coverage to one million. This umbrella policy was relatively cheap (under $200/yr) for my husband and I. Even better, it covers not only Halloween visitors to my home, but also liability resulting from other accidents, which are far more likely to occur.