It looks that this is not the real name of the measurement, the unprintable characters are being replaced when the response is written as JSON.
The easy way to get rid of this probably is to wait for the retention policy to remove it, but I think if you request the response as msgpack we can get at the real measurement name. This response is a binary file:
curl 'http://localhost:8086/query?db=telegraf&q=show+measurements' -H 'Accept: application/x-msgpack' > tmp
It should be possible to extract the measurement name from this and send a “drop measurement” query with curl that removes the measurement.
Probably best to disable the SqlRequests for now as well. I was hoping this was fixed in #6818 but if you are using the latest Telegraf version there may be an additional bug.
