Mishnah Taharos 7:2: One who leaves an am ha'aretz in his house awake and finds him awake, [or leaves him] asleep and finds him asleep, [or leaves him] awake and finds him asleep, [in these three cases] the house is pure. If [one leaves him] asleep and he finds him awake, the house is impure, according to Rabbi Meir. And the Sages say: things are only impure as far as to where he [the am ha'aretz] could extend his hand and touch.

הַמַּנִּיחַ עַם הָאָרֶץ בְּתוֹךְ בֵּיתוֹ עֵר וּמְצָאוֹ עֵר, יָשֵׁן וּמְצָאוֹ יָשֵׁן, עֵר וּמְצָאוֹ יָשֵׁן, הַבַּיִת טָהוֹר, יָשֵׁן וּמְצָאוֹ עֵר, הַבַּיִת טָמֵא, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, אֵין טָמֵא אֶלָּא עַד מְקוֹם שֶׁהוּא יָכוֹל לִפְשֹׁט אֶת יָדוֹ וְלִגָּע:

Mishnah Taharos 7:3: If one leaves craftsmen in his house, the house is impure, according to Rabbi Meir. And the Sages say: things are only impure as far as to where they could extend their hands and touch.

הַמַּנִּיחַ אֻמָּנִים בְּתוֹךְ בֵּיתוֹ, הַבַּיִת טָמֵא, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, אֵין טָמֵא אֶלָּא עַד מְקוֹם שֶׁהֵן יְכוֹלִין לִפְשֹׁט אֶת יָדָם וְלִגָּע: