It varies and they don't talk about it (obviously) but you can glean things from various sources. The more "public" the ultra rich are, the more they'll have security, especially noticeable security.

The silent or unknown ones will often still have something (usually a requirement of their or their company's insurance).

Once you graduate from "2, 3, 5 houses" to "mansions" you will have staff at each one, even if relatively bare-bones.