  We couple a massive spin 2 particle to electromagnetism. By introducing new,
redundant degrees of freedom using the Stueckelberg formalism, we extract an
intrinsic, model independent UV cutoff of the effective field theory describing
this system. The cutoff signals both the onset of a strongly interacting
dynamical regime and a finite size for the spin 2 particle. We show that the
existence of a cutoff is strictly connected to other pathologies of interacting
high-spin fields, such as the Velo-Zwanziger acausality. We also briefly
comment on implications of this result for the detection of high spin states
and on its possible generalization to arbitrary spin.
