Movie or TV show about aliens trapped in concrete

Question

I saw it long ago when I was a child, so bear with me.

• It's a little old, approximate the early 90's

• It's about people (aliens I think, in human form) being trapped inside concrete walls and floor, and being discovered decades later with sonar, and spiked out of the concrete.

• They have been alive the whole time, and are still alive when released from the concrete.

• They have pale skin, and I think there are 2 or 3 of them total.

• Something about steel balls too. I think they are used to transfer conscience.

If this reminds anybody of a movie or TV show, be it new or old, any feedback would be appreciated.

Answer 1

The steel balls thing rang a bell, so I did a bit of research and came up with the First Wave season two episode, "Lost Souls".

From the IMDB plot summary:

While working in a subway tunnel, a jackhammer operator discovers the body of travel writer Francesca Dutton encased in the concrete wall, He is shocked to discover she is still alive and hasn't aged, even though the wall was constructed fifty years before. Posing as her grandson, Cade shows up at the hospital in the hope that she is living proof of an alien experiment. She promises to tell Cade everything he wants to know if he can find "the others". Eddie researches her request and discovers that two more people disappeared the same year -- the only connection being that all three were members of a tour group that visited a monastery in the Himalayas. As they start trying to uncover the whereabouts of these "lost souls", they learn that the truth may be even more horrifying than they thought.

What triggered my memory is I believe the aliens on the show stored their consciousnesses in metal balls. They used human bodies on Earth and only had to send their minds across space.