"Voicemail" contact # is a stranger's home phone number

I just discovered a strange contact in my gmail account named "Voicemail xxxx" with the x's being the last 4 digits of my cell phone number. Pretty sure this is a new contact as of the last time I checked my contact list (within the last 8-12 months).

I then called the number using my Iphone but was surprised to see the number came up as a contact named "Voicemail." When I clicked on the contact, there are 2 versions of a contact for this number, one called "Voicemail" and one named "Voicemail xxxx" (same 4 numbers as in gmail contact."

Additionally, there is a "voicemail" contact listed under the heading "Siri Found in Apps" with the description "Siri found in InCallService."

I already changed the passcode to my voicemail in case this was some kind of scam or hack.

QUESTIONS

• Is this a security issue?
• Should I just delete the contact from my phone and gmail and call it a day?

LESS IMPORTANT QUESTIONS

• Did I just accidentally create a contact and name it voicemail?
• Why would siri automatically name this number "voicemail" using the InCallService?
• What is InCallService?
• Is there an actual phone number to call my voice mailbox that should be there instead?
• Are there potentially multiple contacts in my addressbook with the wrong number associated to them?

ADDITIONAL INFO THAT MAY NOT BE IMPORTANT

• The phone number is linked to the google profile of a stranger who last posted anything in 2012 or 2013.
• I googled the phone number, and there are a ton of unrelated results, a lot for a scammer or spam caller from 2013, but nothing recent.
• There is no gmail correspondence from him in my account.
• Under the google profile auto generated from the phone number, there are 4 links. 3 of them are titled with "[name's] ipad" (with women's names) but the link is for a google profile. The 4th link is for a "yahoo pulse" account with the stranger's name. All links are dead with 404 error.
• When I call the phone number, it does not ring and a voice says "we cannot complete your call, please try again" then hangs up.
• The Iphone I currently use is new, got it a few months ago (Summer 2018).