There is some mystery behind the Sceva episode in Acts 19. I believe the narrative of 1 Samuel 2 about Eli and his sons, Hophni and Phinehas lie behind the pericope.
Recall that Hophni and Phinehas were corrupt (1Sam2.12-17, 27-36). The LXX says that Hophni and Phinehas were "worthless men." The Hebrew text reads "sons of Belial". On Belial, the Anchor Bible Dictionary (ABD) suggests that there may be a play on words between Belial and Baal, "which would suggest the evilness of the two sons" (ABD, "Hophni", 3.285). These two brothers had "turned away from YHWH" [Heb.] / "no regard for the Lord" [LXX] (1Sam2.12).
I was immediately reminded of Jesus' teaching about Beelzebul in Luke 11.15ff. I. H. Marshall (NIGTC, Luke): "The name [Beelzebul] does not occur in Jewish literature, but appears to represent the same figure as Belial in the intertestamental literature. 'Beel' is clearly equivalent to 'Baal', i.e. 'lord'. The second part of the word has been traced to ...'house, high place, temple' (iKi8.13; Is63.15), giving 'lord of the house' (cf. Mt10.25 so Gaston, with reference to Jesus' claim to be 'lord of the temple')."
So, Fitzmyer (AB, Luke): "[T]he use of Beelzebul [in Lk11.15] and Satan in v. 18 suggests that the former has already become merely an alternate name for Satan, as had 'Belial' (1QS1.18,24; 2.5,19,etc.; cf. 2Cor6.15)."
So, I noted some similarities between Luke 11.15ff. and Acts 19.14-16 (and in light of 1Sam2):
1. Both are about casting out evil spirits.
2. Jesus says in Lk 11.19, "If I cast out demons by Beelzebul, by whom do your sons cast them out?" Acts 19.14-16 speaks of sons of Sceva casting out evil spirits.
3. Jesus tells of the 'strong man', "When one stronger that he assails [another] and overcomes him...". Acts 19.16: "And the man in whom the evil spirit was leaped on them, and mastered both of them, and overpowered them." (The Greek does not match between these two text on these terms. However, as I noted above, Belial in 1Sam2 is in the Heb, not LXX, which tells me Luke is remembering or is mindful of the subnarrative in Hebrew.)
4. The evil spirit of Jesus' story says, "I will return to the house from which I came" (Lk11.24). Acts 19.16: "...so that they fled that house...". (The Greek matches here, as it does with 1Sam2 LXX as well.)
5. The evil spirit of Jesus' story "brings seven other spirits more evil than himself, and they enter and dwell there" (Lk11.26). Acts 19.14-16 speaks of seven sons of Sceva.
6. In Luke 11.15ff., the movement is from "spirits" (pl.) to "spirit" (sg., v24) back to "spirits" (pl., v26). In Acts 19.14-16, the movement is from "spirits" (pl., v13) to "spirit" (sg., v15). (This has otherwise been puzzling for commentators of Acts. See my previous post: http://ltdahn-theophilus.blogspot.com/2008/07/sceva-episode-parrt-1.html.)
7. In Luke 11, the movement is from one spirit to seven. In Acts 19, the movement is from seven sons to two ("both", amphoteron). Since there are so many similarities between these two Lucan passages and that of 1 Samuel 2, and considering the reference to "your sons" in Luke 11.19, it therefore is not so puzzling that Luke refers to two ("both") seemingly accidentally. He has the two corrupt sons of a high priest in mind, even though as a subnarrative and not overtly.
Back to 2 Samuel 2, Hophni and Phinehas were greedy (2.13-17,29). They desired the extra portions of the offerings. This is exactly what Jesus condemns in the parables of the unjust steward, the rich fool (who build up his barns, Lk12), the rich mand and Lazarus, etc.
ABD concludes: "Samuel emerges as the true priest of Israel." This is precisely what I have been arguing with reference to Luke's use of Samuel (http://ltdahn-theophilus.blogspot.com/2005/04/luke-jesus-and-samuel.html; http://ltdahn-theophilus.blogspot.com/2007/05/luke-240-52-jesus-child.html). Recall my assertion that in the story of the 12-yr-old Jesus, Luke is showing that Jesus is the "faithful priest" foretold of God in 1 Samuel 2.
Lastly, note the level of irony Luke is using in Acts 19. The sons of Sceva do not cast out the evil spirit, but the evil spirit cast out them! Note the text: "they fled out of that house naked and wounded." Recall Luke 11.24 the evil spirit says to himself, "I will return to my house from which I came." So there is another link between Luke 11 and Acts 19: irony. Luke is playing with his own previous work, recalling to Theophilus the story of Jesus' casting out demons. In this ironic way, Luke is able to rib Theophilus in a narrative in which Theophilus was completely absent. In other words, whereas in the earlier chapters of Acts (chs. 4-13+) Luke was able to show the corruption of the priesthood as it related to Theophilus directly (he may even have been one of the high priests mentioned or alluded to at various points in the earlier chapters!), in Acts 19 there is no such narrative link to Theophilus. So, creatively, Luke has come up with Sceva and his seven sons to conjur up once again the subnarrative of 1 Samuel 2 (the most popular of all corrupted priesthood accounts in Jewish history), just as he had before.
I believe, therefore, that Luke has been using 1 Samuel 2 as a subnarrative for great portions, if not all, of his story of Jesus and the Jesus movement.