I achieved an effect similar to what you're mentioning for a feature I shot this summer. We had our main character hang himself in his apartment after finding out he has a terminal illness. We knew we didn't want to do it live because there were no rigging points in our location so we ended up shooting plates and getting other coverage ("feet fighting against the freedom of the air below them").
For the hanging plate, we contacted our local theatre and used their fly system and wire harnesses. I put up a green cyc behind him and we suspended him 4' off the ground. The harness was put under clothing and our fly wire was threaded through a large hemp rope. For the noose around the neck, we basically created a velcro chocker from hemp and then never connected it to the fly wire. This made it appear like he was hanging by his neck, but he was never in any remote danger and we always made sure he was comfortable.
I should also note that I was working with theatrical professionals trained in the operation of fly systems and rigging. This is not something that it is worth "D-I-Y"ing because it could lead to someone "D-I-E"ing. If you can't afford a stunt coordinator to pull off the effect, just get creative with the coverage. For our coverage shots, we hung a goalpost rig above our actor and had him do a pull-up and kick the chair out from below him.