Wildig, 23, was released by Shrewsbury at the end of the season and, after impressing during a loan spell with the Shrimps towards the end of last term, he has now penned a two-year deal at the Globe Arena.
Boss Jim Bentley, who has now made four new signings this summer, told Morecambe’s official website: “Aaron showed real quality when he was with us last season and really impressed us.
“He settled in really well and will be an excellent addition to the squad.”
Meanwhile, Dugdale, 27, has signed a one-year deal with the option for a further year and is the fifth arrival at the club.
Former Crewe centre-half Dugdale told the club’s official website: “I have known (assistant manager) Ken McKenna for a long time and we have always kept in touch. When I met him and the gaffer they really sold the club to me.
“I have always had the utmost respect for Kenny and everyone I know speaks really highly of (manager) Jim Bentley and I was really happy to sign on.
“Everyone knows Morecambe is a really well-run club and I can’t wait to get going. Being Liverpudlian I know a lot of the lads already and I’m looking forward to getting going.”