No you can only lend out the securities of clients that are themselves on margin or have an explicit borrow agreement (which grants you a kickback of the money made from the stock loan).
Cash accounts without a margin balance cannot be lent out.
ETFs are treated like stocks. That's kind of the point. They can be lent out by your broker if you're on margin.
Mutual funds are opaque. It's up to the fund to decide if they want to make some extra money lending their securities out to speculators. As they're holding the stocks long term and standard securities lending is over collateralized, the risk profile is relatively low compared to the extra return.
Cash accounts without a margin balance cannot be lent out.