A video from a bonus feature of the DVD to Chaplin's 1928 film The Circus shows a woman talking into something she's holding up to her ear.
It appears to be a mobile phone, although they were not invented until the 1970s.
The video shown below has amassed more than two million views on YouTube.
The clip was discovered and uploaded by filmmaker George Clarke from east Belfast.
He claimed the person is a time traveller and that "you just can't explain it. Everybody had the same reaction - it looks like she's talking on a mobile phone."
Clip from 'The Circus'
Belfast filmmaker George Clarke
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