Will mention of a previously undisclosed relative, who will now invite me to the UK, help me to obtain a visa? [closed]

No, while the realms of possibility do not exclude it, success in your case would take a miracle. For starters you are addressing the wrong issues...

You were refused last year because they did not believe you were a genuine visitor and the risk of your going underground in the UK was too great. Now you want to tell them that a relative who you were previously unaware of is sending you an invitation. This doesn't really mitigate the risk of your going underground does it?

The issues for you are about your lifestyle, i.e., you are unemployed, you are dependent on others on a day-to-day basis, and have no significant social or economic connections to Ghana. How does getting an invitation to the UK change any of that?

Also, in your previous refusal they threw some shade on your credibility. Namely they didn't believe you actually had an aunt willing to support you. That was bad enough, but now you propose to double down by adding an additional co-sponsor. This is tantamount to an admission that your circumstances have not changed and in fact they are worse than you originally represented.

While it's true that sometimes long-lost relatives can suddenly appear and offer sponsorship for no apparent reason, it is an applicant pattern viewed with pronounced scepticism on the Sub-Saharan Desk. You would have to explain why a relative is willing to do this for you and yet you were unaware of them last year. That would be an awkward explanation and genuine visitors do not need to make awkward explanations like that.

Against all of this we place the backdrop that Ghana has a mind-numbing 44% refusal rate for entry clearance applications. This is historical data and does not indicate the instantaneous probability of your own application's success. It does, however, indicate that applications should be prepared with extreme diligence.

The visitor rules are in Appendix V of the Immigration Rules.