I might be struck down by physicist for this, but I'm pretty sure the "forces" are as material as anything. Recall that even "solid" matter can be expressed as a wave function, even you or I.
I find this pretty spooky, but what were we thinking about when we thought matter was solid?
I guess the way things appear will be sufficiently convincing and authoritative -- until we look more closely and deeply into the matter. As they say, appearances can be deceiving. Still it is pretty spooky to think of ourselves as "wave functions!" (Of course, I do think we're a tad more than merely that.)