Yes, it belongs. I went thru the pics I took of under my dash and found two of the part you're asking about. I can't say for certain where exactly it goes, but it's under the center section of the dash (sort of above the shifter) because if you look closely you can see the starter button that you push with your foot in both pics. In the second pic the part you're asking about is in the lower left corner. I believe it bolts to the underside of dash somewhere under the gauge panel, maybe a little to the left. I think the circuit breakers are to the right of this thing.....right meaning toward the passenger side. I'd go out and confirm that but it's raining real hard right now (and I still have a boat load of present to wrap).
On my 63 B1, that clip is exactly where 52 M-42 describes. That clip attaches with two cap screws to the underside of the dash and holds the douglas connector shells for the ignition switch and the instrument panel. This clip is also where I have the "mystery ground" attached as well (see my post under "Did M37 Have Turn Signals", dtd 12.22.2012 8:37 AM).
I hope this helps, Is this where you found yours? Right next to the choke cable. I'm going to go out on a limb, The one wire that has the end cap on it is from the ignition switch wire no 85. Look at the wires that connect close by, they clip in as shown in a previous photo.
That Douglas connector with the little angle bracket is not a ground, rather it is just a dead end. They are not supposed to have continuity from the wire to the bracket, as they do not have the internal connection inside the plastic ferrule. To power up the wire the bracket end is discarded and the wire plugged in where needed.
The one behind the dash was for an additional circuit breaker if needed for the M42 command kit light socket.
You will also find them in the lead from the unused turn signal lamp (If you don't have signals) on either inside front fender.