Cases of xenoglossy

Keener gives some ostensible examples of modern xenoglossy:

This sort of supernatural knowledge also appears in an extensive survey of possession reports in traditional China, offered mostly from rural areas over a century ago when these experiences were far more common than they are in urban areas of China today. Informants claimed that some spirits spoke with unusual voices or poetic abilities and noted “northerners speaking the languages of the South, which they did not know.”61 Although most of the study’s informants naturally understood and presumably shaped their reports through the assumptions of their own Christian world view, a range of scholars have continued to find their information useful.62  

61. Voices and poetic abilities: John L. Nevius, Demon Possession and Allied Themes (Old Tappan: Revell, 1894), 46–47, 58 (hereafter, Demon Possession). Nevius (pp. 140–43) defends the reliability of his Chinese informants, interestingly noting on p. 143 that their reports are consistent with those from other cultures and eras. As William M. Ramsay also noted (The Teaching of St. Paul in Terms of the Present Day [2nd ed.; London: Hodder & Stoughton, 1913], 105–6), it was only Nevius’s field experience that convinced him that spirit possession was genuine (Nevius, Possession, ix, 9–13; “informants” quotation from ibid.). The use of allegedly alien dialects also appears in some other reports (Horton, “Types,” 29; Shorter, Witchdoctor, 183). 

62. Cf. the use of various missionary reports in Oesterreich, Possession, 143–46, 213–15, 219–23, 229, 362–64. 

https://www.ibr-bbr.org/files/bbr/bbr20b04.pdf

This is germane to the cessationist/continuationist debate.  Cessationists typically contend that glossolalia is xenoglossy. But even if that identification is correct (which is disputable), if there are well-attested examples of xenoglossy in post-apostolic times, then that disproves cessationism on its own terms. 

Mind you, I've read cessationists who attempt to evade this by claiming that even if there were instances of modern xenoglossy, that wouldn't be a "gift," but a one-off event. Of course, that tactic renders cessationism empirically unfalsifiable. 

One problem with Keener's documentation in this case is that he summarizes the material rather than giving specific examples. That makes it harder to evaluate the evidence. One would need to look up the references. Since I'm not charismatic, it's not incumbent on me to hunt it down. I'm not investing in proving it. But for Christians who wish to defend modern xenoglossy, it might be a worthwhile exercise.