The 27-year-old left the Blues for French Top 14 side Toulon in 2014 but his contract expires in the summer.
The Wales international full-back was sat in the stands at the Cardiff Arms Park as the Blues beat the Dragons 27-16 in the Welsh derby on Boxing Day.
"It was great to see him and I know he was quickly back on the plane to his duties in France," Wilson said.
Blues chief executive Richard Holland said earlier in December that they offered Halfpenny a deal to bring him back to Wales.
Speaking after Toulon beat Scarlets in France in the European Champions Cup earlier in December, Halfpenny said he was "weighing up" his options.
"Leigh's obviously got a lot of colleagues and friends from his time with the Blues at the Arms Park," Wilson continued.
"Being home for Christmas I'd imagine with the derby being on his doorstep it was a natural game for him to go and watch."
Halfpenny, who has won 66 caps for Wales, played for Blues for six years before his move to France two years ago.
"I saw him briefly after the game and had a catch up. It's been well documented and I think everybody would like to see Leigh back in Wales," said Wilson.
"Those things are very much ongoing."
Cardiff Blues head coach Danny Wilson says it would be good to see Leigh Halfpenny return to Wales