Can chameleons be let aflone for a few days?

Is it safe or should I get somebody to look in on him?

It depends on if you have left enough food and water, as well as a dependable mist system, proper heating and lighting system on a good timer. If everything is set, then I am sure your chameleon will do fine for at least a few days. There are even people leaving their chameleons at home alone for weeks without anyone coming in to check on them, and they did just fine.

Chameleons are hardy creatures and they live largely solitary lives in nature. In fact, they appear to be flustered by too much attention, they appear to be shy, calculating and cautious. As long as you have left enough food and water, they should be fine. One should not let them out in the open because they are likely run into cats who are hostile to them. A dry environment is okay since its not conducive to diseases.