this is part of the DISA system in the E36 M42 engine.
it controls a flap door that selects air flow between the long and short runners of the intake manifold.
if you have an E36 management and wiring harness - than all the required parts are there and you should only connect that.
it goes underneath the intake manifold, and two screws are holding it to the manifold support bracket.
hope that helps
Ron