In the Name of Allah, The Most Gracious, Most Merciful
(The Prophet (PBUH) used to observe I'tikaf for ten days every year. In the year in which he passed away, he observed I'tikaf for twenty days.")
If one is able to devote himself to worship at the end of Ramadan during the last ten days of it, let him stay in Masjid, but if he cannot in Masjid let him stay at home or stay away from any matter that may disturb his life and serenity.
I want to make it easy, if one of you have the ability to stay away from work because he is his own boss and is not obliged to go to work every day, he may observe I'tikaf in the Masjid, and this is the perfect way of observing I'tikaf. In case he cannot, he may do that at home, which is also very good. In case he also cannot, his I'tikaf might be manifested in staying away from any matter that might disturb his serenity during the last ten days of Ramadan.