Ronda Rousey -- Thanks David Spade, But ... Peeing Is More Dangerous Than the WWE

Ronda Rousey doesn't want her pal David Spade worrying about her getting into WWE, and took a few moments to let him -- and all her fans -- know why she's determined to wrestle, and why it's low risk ... for her.

Ronda was leaving a book signing Thursday night when we asked her about Spade's comment that she should quit pining for pro wrestling ... because she might get hurt and screw up her UFC career.

Watch ... Ronda not only explains why she's still determined to return to the WWE, but also smacks down Spade's concerns. As she puts it ... she's more likely to stub a toe at home, than get injured while wrestling.