You may find some speculations on the imaginary "wormholes", but it is nothing more than a notion. No proof, no examples, and as OP said, kind of impossible. BH do not connect to anywhere, in my thinking, a BH is the result of a gravitational event; no other force is needed, and once formed, there is so much compression (gravity) that even the atoms get packed so tight they lose coherence and structure, we think. No one knows about BH, we can only speculate. If a BH has any "connection", think of the forces that connection would have to overcome; also, a BH is a local event, and consists of local material, so how can that crushed mass "lead" to anywhere? It's the most solid thing in the Universe. If there are any connections, they would be in a higher dimension, of which we know nothing, so the simple answer points to NO, wormholes are not connected with BHs.