Although Paul is not specific about the "evils" he practiced, (vs 19.) we know that they were a culmination of sins that were counter to his mindful desires not to do them, but did them as a result of a mind vs. flesh struggle. To be more specific it's necessary to examine the context of Romans chapter 7.
Romans chapter 7 verses 7-25 are the subject of much controversy in evangelical circles. Some feel Paul is describing the struggle between "flesh and Spirit" within the carnal Christian. Others believe Paul may have described his then current struggles with sinful desires. But there's good reason to believe that Paul described his past struggles with sin (or evil) as an unconverted Jew attempting justification through the Law as opposed to Christ the Deliverer.
Gentiles (believers and nonbelievers) were never under Mosaic Law. Jews, from the time of birth, were saturated with the Mosaic Law. Instead of acknowledging the purposes of the law and realizing their need of a savior, it was common for Jews to hold their descent from Abraham and bond with the law as means of salvation (See Matthew 3:9).
Paul, a former Pharisee, described himself as one who "delights in the Law of God in my inner being" (7:22).
Rom 7:22 For I delight in the law of God, in my inner being,*
The inner being he speaks of we commonly call the mind (see vs 23). Paul's mind had been in continual conflict with his flesh. He shows that his mind was no match with his flesh; the flesh being the part of human beings corrupted by sin.
Rom 7:14 For we know that the law is spiritual, but I am of the
flesh, sold under sin
Rom 7:17 So now it is no longer I who do it, but sin that dwells
Summmary: The "evil" Paul speaks of is not specific to anything but are sins the result of Paul's mind being in submission to the corrupted nature of sin pass down to every human by Adam.
Rom 8:14 clearly shows that Paul is not referring to a believer. Someone "sold under sin" is contrary to the believer described in Romans 6 as, "...one who has died has been set free from sin" (Romans 6:7).
When Paul refers to "members" he speaks of his limbs (or other body parts) that are similarly in submission to the flesh. Paul may have had verses like these in mind. No way to be sure. The word hands appear in scripture as instruments of evil.
Ecc 5:6 Let not your mouth lead you into sin, and do not say before
the messenger that it was a mistake. Why should God be angry at your
voice and destroy the work of your hands
Jer 25:14 For many nations and great kings shall make slaves even of
them, and I will recompense them according to their deeds and the work
of their .
Psa 119:101 I hold back my feet from every evil way, in order to
keep your word.
An excellent book on the subject of Romans 7. Link below.