I was an actuarial science/finance major in college and am a fully-credentialed actuary. Now I am applying to master's programs for FE.
I think through an actuarial science degree you can take some of the courses that are very useful for future FE studies, like calculus-based probability, statistical inference, stochastic processes and math of investments. Of course you should also add classes from other departments to create the desired background. I was an undergrad in NYU so I was able to access classes in both Stern and Courant to tailor my curriculum up a bit to include some math and finance classes.
You can be an actuarial science major and take mechanical engineering classes and vice versa.