It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Kill the gecko, even if it is inside the Ka'bah."
Hadith Referenceالمعجم الأوسط / باب الميم / 6301
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 11495»