Deterrents

Most break-ins are opportunistic. A house that looks watched, occupied or difficult gets passed over for the one that doesn't.

Dummy cameras, signage and occupancy simulation cost very little and work on exactly the sort of intruder who was never going to try very hard.

Being straight with you: a fake camera deters someone scanning for an easy target. It does nothing to a person who has decided on your house specifically. Use these as a layer, not as your only measure.