Wire a 220 power cord to a sign in a metal frame
Mantraps and such are illegal. Now if this happened at night, and there is a castle doctrine, and you are armed to protect property, you have a better chance in criminal court, just be ready for civil court. But then these snowflakes will take you to civil court merely for you saying “boo!” to them.
110 will do it, and with a puddle of water, it can be permanent.