  An invariant random subgroup $H \leq G$ is a random closed subgroup whose law
is invariant to conjugation by all elements of $G$. When $G$ is locally compact
and second countable, we show that for every invariant random subgroup $H \leq
G$ there almost surely exists an invariant measure on $G/H$. Equivalently, the
modular function of $H$ is almost surely equal to the modular function of $G$,
restricted to $H$.
  We use this result to construct invariant measures on orbit equivalence
relations of measure preserving actions. Additionally, we prove a mass
transport principle for discrete or compact invariant random subgroups.
