This is in response to the OP's recent reference request.
It sounds like the reference you seek may be John Milnor's paper
Construction of universal bundles. I. Ann. of Math. (2) 63 (1956), 272–284.
Milnor constructs a universal bundle whose fibre is the space of "simplicial loops", by analogystarts with Serre's loop spacethe Serre path-loop fibration with fibre $\Omega X$ on a based countable simplicial complex $X$. He then replaces continuous paths (loops) with "simplicial paths (loops)". It turns out that thisthe resulting bundle is still universal (meaning the space of based simplicial paths is contractible) and the fibre $\tilde{\Omega} X$, the space of based simplicial loops, is now a topological group.